Metals and Non-metals: Class 10 Science Chapter 3 Hinglish mein

Science · Hinglish notes, simulations aur practice · Official NCERT chapter PDF ↗

Published 12 Oct 2026 · Updated 12 Oct 2026

105 min
35 practice questions
24 MCQs

Is chapter mein aap kya seekhenge

Metals aur non-metals ko lustre, hardness, malleability, ductility, conduction aur sonority ke basis par compare karo, aur important exceptions ke naam batao
Oxides ko basic, acidic ya amphoteric mein classify karo, aur metals ke oxygen, water aur dilute acids ke saath reactions ki balanced equations likho
Experimental evidence se reactivity series banao aur usse displacement reactions predict karo
Electron-dot structures se dikhao ki electron transfer se ionic compounds kaise bante hain, aur unki properties samjhao
Batao ki metals ko reactivity series mein unki jagah ke hisaab se kaise concentrate, extract aur refine kiya jaata hai
Rusting ki conditions samjhao, aur batao ki coatings, galvanising aur alloying se corrosion kaise roka jaata hai

NCERT Science Class 10, Chapter 3, pp. 37–57 par based original companion text. Yeh NCERT se juda nahi hai aur NCERT ne ise endorse nahi kiya hai.

Kitchen mein charon taraf dekho. Pressure cooker aluminium ya steel ka hai, tap aksar brass ka hota hai, aur gas stove mein copper aur steel ke parts hain. Ab angithi ke coal, maachis ki dibbi ke sulphur aur hamari saans wali oxygen ke baare mein socho. Yeh un bartanon jaise bilkul nahi behave karte. Class 9 mein tum elements se mile the, sabse simple pure substances ke roop mein. Chemists inmein se zyaadatar ko do badi families mein baantte hain: metals (धातु) aur non-metals (अधातु).

Yeh chapter poochta hai ki ek metal ko metal kya banata hai. Pehle hum physical properties test karte hain, phir dekhte hain ki metals oxygen, water, acids aur ek doosre ke salts ke saath kaise react karte hain. Yeh results line mein lagkar reactivity series ban jaate hain. Phir yahi series samjhaati hai ki metals ions kyun banate hain, unhe rocks se kaise nikaala aur purify kiya jaata hai, aur kyun iron mein rust lag jaata hai jabki gold sadiyon tak chamakta rehta hai.

3.1 Physical Properties

Materials mein farq karne ka sabse jaldi tareeka hai unhe dekhna, thokna, modna, aur check karna ki unse heat ya electricity guzarti hai ya nahi. Inmein se koi bhi test substance ki banawat nahi badalta, isliye yeh uski physical properties dikhate hain.

3.1.1 Metals

Ek naya steel spoon, ek copper wire aur aluminium foil ki ek sheet uthao. Teenon chamakte hain, chhoone mein thande lagte hain, aur tootne ke bajaye mud jaate hain. Chalo in features ko ek-ek karke test karte hain, iron, copper, aluminium, magnesium, zinc aur lead ke samples ke saath (Fig. 3.1).

5/5Lustre, malleability, ductility aur sonority metals ki typical properties hain.

Fig. 3.1Metal ke liye chaar quick tests.

Chhote scenes ka ek two-by-two grid. Step 1 top-left scene highlight karta hai: sandpaper ek dull metal strip ko ragadta hai aur ek bright, chamakdaar patch chhodta hai, jis par lustre likha hai. Step 2 top-right scene highlight karta hai: hammer ne iron block par rakhe metal ke tukde ko chapta karke chaudi patli sheet bana diya hai, jis par malleable likha hai. Step 3 bottom-left scene highlight karta hai: ek moti rod steel plate ke chhed se kheenchi jaati hai aur lambi patli wire ban kar nikalti hai, jis par ductile likha hai. Step 4 bottom-right scene highlight karta hai: metal ki ghanti par chot lagti hai aur sound waves phailti hain, jis par sonorous likha hai. Step 5 chaaron scenes ek saath dikhata hai.

Activity 3.1NCERT Activity 3.1 · p. 37

Chamak kahan se aati hai?

Tumhe chahiye

ek dull pada copper wire
ek purani iron ki keel
aluminium ki ek strip
magnesium ribbon ka ek tukda
sandpaper ki ek sheet

Pehle guess karo

Dull copper wire ko sandpaper se ragadne par wahan kya dikhega?

Wahi dull brown rangEk bright, chamakdaar surfacePoore andar tak kaala powder

Har sample ko achhi roshni mein dekho aur note karo ki uski surface kaisi dikhti hai.
Har sample ka ek chhota patch sandpaper se tab tak ragdo jab tak woh badal na jaaye.
Ragde hue patch ko baaki surface se compare karo.

Activity 3.2NCERT Activity 3.2 · p. 37

Kya chaaku metal ko kaat sakta hai?

Tumhe chahiye

iron, copper, aluminium aur magnesium ke chhote tukde
ek tez chaaku aur ek wooden board
teacher ke liye: oil mein rakha sodium, tongs, filter paper aur ek watch-glass

Board par har metal ke tukde par chaaku ek-ek karke zor se dabao.
Dekho kaise teacher tongs se sodium ka chhota tukda oil se nikaalte hain, use filter paper ki sheets ke beech sukhaate hain aur watch-glass par kaatte hain.
Compare karo ki har cut mein kitni mehnat lagti hai.

Mithai ki dukaan wale kaju katli ko varq se sajaate hain, yeh silver itna patla peeta jaata hai ki tissue paper ki tarah phat jaata hai. Bina crack hue hammer ya roll karke patli sheets ban jaane ki property ko malleability (आघातवर्ध्यता) kehte hain. Malleable metals ki list mein gold aur silver sabse upar hain.

Definition

Malleable

Jise bina toote peet kar ya roll karke patli sheets mein badla ja sake.

ExampleRotiyan pack karne ke liye aluminium foil; mithai par silver varq.

Jo metal khinch kar patli wire ban sake woh ductile hai, aur is property ko uski ductility (तन्यता) kehte hain. Gold se zyaada ductile koi metal nahi: uske sirf ek gram ko ek kilometre se lambi wire mein kheencha ja sakta hai. Malleability aur ductility milkar hamein metals ko har kaam ke hisaab se sheets, rods, bartan aur wires ki shape dene dete hain.

Definition

Ductile

Jise kheench kar patli wires banaayi ja sakein.

ExampleElectric wiring ke liye copper; guitar strings ke liye steel.

Zyaadatar cooking bartan aluminium, steel ya copper ke hote hain, jabki unke handles aksar wood ya plastic ke hote hain. Pan ke liye metal kyun, lekin handle ke liye kyun nahi? Activity 3.5 check karta hai ki metal heat ko kitni achhi tarah le jaata hai.

Activity 3.5NCERT Activity 3.5 · p. 38

Baari-baari girti pins

Tumhe chahiye

lagbhag 20 cm lambi copper ya aluminium strip
clamp wala ek stand
teen drawing pins
candle wax
ek spirit lamp ya candle

Pehle guess karo

Kaun si pin sabse pehle giregi?

Flame ke sabse paas wali pinFlame se sabse door wali pinTeenon ek hi pal mein

Strip ka ek end clamp karo taaki strip side mein bahar nikli rahe.
Pighle wax ki boondon se teen pins strip ke neeche uske free end se 5 cm, 10 cm aur 15 cm par chipkao.
Free end ko flame mein garam karo aur pins ko dekho.
Note karo ki strip khud pighalti hai ya nahi.

Electric wire ka end chheelo to PVC plastic ke jacket ke andar bright copper ya aluminium ke strands milte hain. Strands current le jaate hain; jacket isliye hai taaki wire chhoone wale insaan mein current na jaa sake. Activity 3.6 ek simple tester banata hai jo check karta hai ki koi solid electricity conduct karta hai ya nahi.

1/3Copper gap band karta hai: bulb jalta hai.

Fig. 3.2Ek simple conduction tester.NCERT Fig. 3.2 · p. 39

Do cells, ek bulb aur wires ek loop banate hain jiske neeche ek gap hai, jahan sample do crocodile clips ke beech pakda jaata hai. Step 1 mein sample ek copper chaabi hai aur bulb jalta hai, arrows dikhate hain ki current loop mein ghoom raha hai. Step 2 mein sample sulphur ka ek peela tukda hai aur bulb andhera rehta hai, jis par no current likha hai. Step 3 mein sample graphite ka bana pencil lead hai aur bulb phir jalta hai, yaani yeh non-metal conduct karta hai.

Ek steel spoon aur ek wooden spoon zameen par giraao. Steel wala khanakta hai; wooden wala bas thud karta hai. Jo metals chot lagne par khanakti awaaz dete hain woh sonorous hote hain. Isiliye school ki ghanti, mandir ki ghanti, ghungroo aur cymbals metal ke bante hain.

3.1.2 Non-metals

Elements mein se sirf thode hi non-metals hain, lekin woh bahut important hain: hawa ki oxygen aur nitrogen, har living cheez mein carbon, bleach mein chlorine, iodised namak mein iodine, maachis ki teeli ke sire par sulphur. Room temperature par inmein se zyaadatar gases ya brittle solids hain; laal-bhoora bromine akela liquid hai. Kya yeh woh tests pass karte hain jo metals karte hain? Try karke dekho.

Activity 3.7NCERT Activity 3.7 · p. 39

Non-metals par bhi wahi tests karo

Tumhe chahiye

charcoal ya coal ka ek tukda
ek pencil lead (graphite)
sulphur ka ek tukda
pichhli activities ke metal samples
Activity 3.6 wala conduction tester

Activities 3.1 se 3.4 ke chamak, kaatne, hammer aur wire wale tests har non-metal par dohrao.
Har sample ko conduction tester mein clip karo.
Har result table mein likho, saath mein teen metals ke results bhi.

Table 3.1Metals aur non-metals aamne-saamne

Sample	Chamakta hai?	Hard hai?	Chapta hota hai?	Conduct karta hai?	Khanakta hai?
Copper
Aluminium
Iron
Charcoal
Sulphur
Pencil lead

Tumhari entries apne aap save hoti hain.

Tumhari table saaf trends dikhati hai, lekin Table 3.2 dikhata hai ki har trend ke exceptions hain. Isliye sirf physical properties se saare elements ko sort nahi kiya ja sakta.

Table 3.2Rules aur unke exceptions

Aam rule	Exception
Metals room temperature par solid hote hain	Mercury liquid hai
Metals sirf high temperatures par pighalte hain	Gallium aur caesium garam hatheli par pighal jaate hain
Metals hard hote hain	Lithium, sodium aur potassium makhan ki tarah kat jaate hain; yeh halke bhi hain aur aasaani se pighalte hain
Non-metals dull hote hain	Iodine crystals mein metallic lustre hota hai
Non-metals soft ya brittle hote hain	Diamond, jo carbon ka ek form hai, kisi bhi doosre natural material se zyaada hard hai, aur sirf bahut high temperatures par pighalta aur boil hota hai
Non-metals conduct nahi karte	Graphite, carbon ka ek aur form, electricity conduct karta hai

Diamond aur graphite dono pure carbon hain. Ek hi element ke alag forms, jinmein atoms alag tarah se arranged hote hain, allotropes kehlaate hain. Arrangement properties ko poori tarah badal deta hai: ek nature ka sabse hard substance hai, doosra itna soft ki usse likh sakte ho.

Compare

Metals aur non-metals: physical properties

Metals

Lustrous
Aam taur par hard; malleable aur ductile
Heat aur electricity ke achhe conductors
Sonorous
Solids, mercury ko chhodkar

Non-metals

Zyaadatar dull (iodine chamakta hai)
Solid roop mein brittle; na malleable na ductile
Poor conductors (graphite electricity conduct karta hai)
Sonorous nahi
Solids ya gases; bromine liquid hai

Kyunki physical rules mein exceptions hain, chemists element ko classify karne ke liye chemical behaviour par zyaada bharosa karte hain. Ek achha pehla test hai element ko jalaana aur pata karna ki woh kis tarah ka oxide banata hai.

Activity 3.8NCERT Activity 3.8 · p. 40

Kis tarah ka oxide?

Tumhe chahiye

magnesium ribbon ki 3 cm strip
deflagrating spoon mein thoda sa sulphur powder
tongs aur ek burner
ek test tube, ek watch-glass aur water
red aur blue litmus paper

Pehle guess karo

Jalte magnesium ki white raakh ko water mein milaaya jaata hai. Yeh red litmus ke saath kya karegi?

Use blue kar degiUse red hi rehne degiUse bleach karke white kar degi

Tongs se magnesium ribbon ko flame mein pakdo aur white raakh watch-glass par ikattha karo.
Raakh mein paani ki kuch boondein milaao aur use pehle red, phir blue litmus paper se chhuao.
Sulphur ko tab tak garam karo jab tak aag na pakad le, aur gas pakadne ke liye uske upar ulti test tube rakho.
Test tube mein thoda water daalo, hilaao, aur liquid ko dono litmus papers se test karo.
Dono jalne ki equations likho.

4/4Water mein gas blue litmus ko red karti hai: acidic oxide.

Fig. 3.3Metal oxide aur non-metal oxide ulta behave karte hain.NCERT Activity 3.8 · p. 40

Do columns. Step 1 mein tongs se pakda magnesium ribbon roshni ke chamakte taare ki tarah jalta hai aur white raakh chhodta hai. Step 2 uske neeche ek dish mein water ke saath mili raakh dikhata hai, saath mein red litmus ki strip jo blue ho gayi hai, jis par basic likha hai. Step 3 right column mein spoon mein jalta sulphur dikhata hai, jiske upar ulti test tube gas ikattha karti hai. Step 4 uske neeche water wali test tube dikhata hai, saath mein blue litmus ki strip jo red ho gayi hai, jis par acidic likha hai.

Magnesium jalta hai

2 M g + O_{2} \overset{}{\to} 2 M g O

(3.1)

Ek basic solution

\begin{aligned} M g O + H_{2} O \\ \overset{}{\to} M g (O H)_{2} \end{aligned}

(3.2)

Sulphur jalta hai

S + O_{2} \overset{}{\to} S O_{2}

(3.3)

Ek acidic solution

\begin{aligned} S O_{2} + H_{2} O \\ \overset{}{\to} H_{2} S O_{3} \end{aligned}

(3.4)

jahan

$H_{2} S O_{3}$: sulphurous acid

Practice · 2 questions

Practice: physical properties (NCERT in-text questions, p. 40): answers ke saath

1
Short answerEasyNCERT in-text Questions p. 40, Q1
Har description par fit hone wale ek metal ka naam batao.
1. Thandi subah mein yeh bottle se beh kar bahar aa jaayega.
  Solution dikhao
  AnswerMercury
  Mercury akela metal hai jo room temperature par liquid hai.
2. Teacher ise table knife se kaat sakte hain.
  Solution dikhao
  AnswerSodium (ya potassium, lithium)
  Alkali metals lithium, sodium aur potassium itne soft hain ki chaaku se kat jaate hain.
3. Agar keemat ki parwaah na ho, to isse sabse jaldi garam hone wala pan banega.
  Solution dikhao
  AnswerSilver
  Saare metals mein silver heat sabse achha conduct karta hai, aur copper uske theek peechhe hai.
4. Zyaadatar metals ke muqaable yeh heat kam conduct karta hai.
  Solution dikhao
  AnswerLead (ya mercury)
  Metals mein lead aur mercury heat ko kaafi bura le jaate hain.
Short answerEasyNCERT in-text Questions p. 40, Q2
Ek sunaar gold ke ek daane ko hammer se itna patla patra bana deta hai ki usmein se roshni dikhti hai, aur doosre daane ko kheench kar earring ke liye patli wire bana deta hai. Har case mein gold ki kaun si property use hui, naam batao aur uska matlab samjhao.
Solution dikhao
AnswerPatre ke liye malleability; wire ke liye ductility.
Patra malleability use karta hai: malleable metal ko bina crack hue hammer ya roll karke patli sheets banaya ja sakta hai.
Wire ductility use karti hai: ductile metal ko stretch ya draw karke patli wires banaya ja sakta hai. Gold saare metals mein sabse zyaada malleable aur sabse zyaada ductile hai.

3.2 Metals ki Chemical Properties

Is section mein tum metals ko oxygen, water, dilute acids aur doosre metals ke salts ke solutions ke saath react karte dekhoge. Samples ka ek set taiyaar rakho: aluminium, copper, iron, lead, magnesium aur zinc, saath mein teacher ke demonstrations ke liye sodium. Dekho ki har ek kitni tezi se react karta hai, kyunki speed batati hai ki metal kitna reactive hai.

3.2.1 Metals ko Hawa mein jalaane par kya hota hai?

Activity 3.9NCERT Activity 3.9 · p. 41

Kaun se metals jalte hain?

Tumhe chahiye

sample metals ke chhote tukde ya powders
tongs aur ek burner
safety goggles

Teacher har sample ko tongs se flame mein pakadte hain.
Note karo ki woh jalta hai ya nahi, flame ka rang kya hai, aur thanda hone ke baad surface kaisi dikhti hai.
Jo bhi product bane use ikattha karo aur check karo ki woh water mein ghulta hai ya nahi.
Metals ko is hisaab se rank karo ki woh oxygen ke saath kitni aasaani se judte hain.

Table 3.3Flame mein metals

Metal	Jalta hai?	Flame ka rang	Product aur woh kaisa dikhta hai
Magnesium
Aluminium
Zinc
Iron
Copper
Lead

Tumhari entries apne aap save hoti hain.

Zyaadatar metals ko hawa mein garam karo to woh oxygen le lete hain aur metal oxide ban jaate hain:

\begin{aligned} metal + oxygen \\ ⟶ metal oxide \end{aligned}

(3.5)

Flame mein pakdi gayi bright copper wire kaali hokar nikalti hai, kyunki us par copper(II) oxide ki ek parat ban jaati hai. Aluminium powder jal kar white aluminium oxide deta hai:

2 C u + O_{2} \overset{}{\to} 2 C u O

(3.6)

\begin{aligned} 4 A l + 3 O_{2} \\ \overset{}{\to} 2 A l_{2} O_{3} \end{aligned}

(3.7)

Chapter 2 mein metal oxides ko bases maana gaya tha, aur zyaadatar hain bhi: jaise kaala copper(II) oxide dilute hydrochloric acid mein ghul kar blue-green salt solution deta hai. Aluminium oxide aur zinc oxide do-rukhe hain. Acid mein woh base ki tarah use neutralise karte hain; sodium hydroxide solution mein woh acid ki tarah use neutralise karte hain. Dono hi tarah se salt aur water bante hain. Is dohre behaviour wale oxides ko amphoteric oxides (उभयधर्मी ऑक्साइड) kehte hain.

Definition

Amphoteric oxide

Aisa metal oxide jo acids aur bases dono ke saath react karke salt aur water banata hai.

ExampleAluminium oxide, $A l_{2} O_{3}$ , aur zinc oxide, $Z n O$ .

Base ki tarah

\begin{aligned} A l_{2} O_{3} + 6 H C l \\ \overset{}{\to} 2 A l C l_{3} + 3 H_{2} O \end{aligned}

(3.8)

Acid ki tarah

\begin{aligned} A l_{2} O_{3} + 2 N a O H \\ \overset{}{\to} 2 N a A l O_{2} + H_{2} O \end{aligned}

(3.9)

jahan

$N a A l O_{2}$: sodium aluminate, ek salt

Example 3.1

Zinc oxide dono taraf

Zinc oxide calamine lotion ka white powder hai. Dilute hydrochloric acid aur sodium hydroxide solution ke saath iske reactions ki balanced equations likh kar dikhao ki yeh amphoteric hai. Base ke saath bana salt sodium zincate, $N a_{2} Z n O_{2}$ , hai.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Zyaadatar metal oxides ko water mein daalo to woh bas pade rehte hain. Sodium oxide aur potassium oxide alag behave karte hain: woh ghul kar react karte hain, aur ek strongly alkaline solution chhodte hain (alkali woh base hai jo water mein ghul jaata hai):

\begin{aligned} N a_{2} O + H_{2} O \\ \overset{}{\to} 2 N a O H \end{aligned}

(3.10)

Potassium oxide bhi isi tarah react karke potassium hydroxide, $K O H$ , deta hai. Activity 3.9 ne yeh bhi dikhaya ki metals oxygen ke saath bahut alag speeds par react karte hain, jaisa Table 3.4 mein summary hai.

Table 3.4Kuch metals oxygen ke saath kaise behave karte hain

Metal	Oxygen ke saath	Isliye hum…
Potassium, sodium	Khuli hawa mein itni tezi se react karte hain ki aag pakad sakte hain	unhe kerosene mein, hawa aur nami se door rakhte hain
Magnesium, aluminium, zinc, lead	Room temperature par patli oxide parat ban jaati hai	parat par bharosa karte hain: yeh metal ko aage ke attack se bachaati hai
Iron	Tukda nahi jalta, lekin flame mein baareek filings chingaariyon ke saath jalti hain	iron filings se bani phuljhadi (sparkler) ki chingaariyon ka maza lete hain
Copper	Jalta nahi; garam copper par $C u O$ ki kaali coat aa jaati hai	coat ko dilute acid se saaf karte hain
Silver, gold	Tez garam karne par bhi react nahi karte	unhe jewellery aur coins ke liye use karte hain

Ab tak saaf hai ki hamare samples mein sodium sabse zyaada reactive hai, aur uske baad magnesium aata hai. Lekin jalaane se zinc, iron, copper aur lead ko ek doosre ke muqaable rank nahi kiya ja sakta. Hamein doosre tests chahiye.

3.2.2 Metals Water ke saath react karein to kya hota hai?

Activity 3.10NCERT Activity 3.10 · p. 42

Thanda water, garam water, steam

Tumhe chahiye

sample metals ke chhote tukde
thande water aur garam water ke beakers
steam ke liye: geele glass wool wali boiling tube, ek burner aur ek delivery tube

Teacher har metal ka chhota tukda aadhe bhare thande water ke beaker mein daalte hain. Note karo ki kaun react karte hain, kitni tezi se, aur koi metal tairta hai ya aag pakadta hai.
Jin metals mein koi badlaav nahi dikhta, unhe garam water mein try kiya jaata hai.
Jinmein phir bhi koi badlaav nahi dikhta, unhe geele glass wool se aane wali steam mein tez garam kiya jaata hai; jo bhi gas bane use bahar le jaakar jalti teeli se test kiya jaata hai.
Metals ko is hisaab se rank karo ki woh water ke saath kitni aasaani se react karte hain.

4/4Pb, Cu, Ag aur Au water ke saath koi reaction nahi dikhate.

Fig. 3.4Water ke saath react karne ke liye zaroori conditions ke hisaab se sort kiye gaye metals.NCERT Fig. 3.3 · p. 43

Chaar rows ki ek seedhi, har step mein ek row khulti hai. Step 1, thanda water: potassium, sodium aur calcium, saath mein note ki reaction violent ho sakta hai. Step 2, garam water: magnesium, jo dheere react karta hai aur tairta hai. Step 3, steam: aluminium, zinc aur iron, jo oxide aur hydrogen dete hain. Step 4, koi reaction nahi: lead, copper, silver aur gold. Side mein neeche ki taraf ek arrow par less reactive likha hai.

Water oxygen se zyaada naram attacker hai, isliye yeh metals ko aur baareeki se sort karta hai. Jab bhi koi metal water ke saath react karta hai, ek product hydrogen gas hota hai; doosra metal oxide hota hai, ya agar woh oxide ghul jaaye to metal hydroxide. Fig. 3.4 ki seedhi par ek-ek paaydaan neeche utro.

Thanda water, violently: potassium aur sodium. Chhota tukda surface par sarsaraate hue fisalta hai aur itni heat deta hai ki hydrogen aksar aag pakad leti hai:

Bahut violent; heat nikalti hai

\begin{aligned} 2 K + 2 H_{2} O \\ \overset{}{\to} 2 K O H + H_{2} \end{aligned}

(3.11)

Violent; heat nikalti hai

\begin{aligned} 2 N a + 2 H_{2} O \\ \overset{}{\to} 2 N a O H + H_{2} \end{aligned}

(3.12)

Thanda water, dheere se: calcium. Yeh lagaataar bubbles deta hai, lekin itni kam heat nikalti hai ki hydrogen jal nahi paati. Jaldi hi tukda upar uth kar tairne lagta hai, us par chipke hydrogen bubbles use utha lete hain:

\begin{aligned} C a + 2 H_{2} O \\ \overset{}{\to} C a (O H)_{2} + H_{2} \end{aligned}

(3.13)

Garam water: magnesium. Thanda water ise mushkil se chhoota hai. Garam water mein yeh dheere-dheere magnesium hydroxide aur hydrogen deta hai, aur yeh bhi aakhir mein apne hi bubbles par tairne lagta hai:

Garam water ke saath

\begin{aligned} M g + 2 H_{2} O \\ \overset{}{\to} M g (O H)_{2} + H_{2} \end{aligned}

(3.14)

Sirf steam: aluminium, zinc aur iron. Thanda aur garam water inhe kuch nahi karte, lekin steam mein laal-garam metal oxide aur hydrogen deta hai:

\begin{aligned} 2 A l + 3 H_{2} O (g) \\ \overset{}{\to} A l_{2} O_{3} + 3 H_{2} \end{aligned}

(3.15)

\begin{aligned} Z n + H_{2} O (g) \\ \overset{}{\to} Z n O + H_{2} \end{aligned}

(3.16)

Example 3.2

Iron aur steam ki equation balance karna

Laal-garam iron steam ke saath react karke hydrogen aur kaala, magnetic oxide $F e_{3} O_{4}$ deta hai. Balanced equation likho.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Water lead, copper, silver aur gold ko kuch nahi karta, chahe woh thanda ho, garam ho ya steam. Yeh ek wajah hai ki copper water pipes aur tanks ke liye achha choice hai, aur silver aur gold ke gehne baarish mein bhi chamakte rehte hain.

3.2.3 Metals Acids ke saath react karein to kya hota hai?

Chapter 2 mein dikha tha ki dilute acids bahut se metals par attack karte hain, aur hydrogen gas aur ek salt banate hain:

\begin{aligned} metal + dilute acid \\ ⟶ salt + hydrogen \end{aligned}

(3.17)

Kya saare metals acids ke saath react karte hain, aur utni hi tezi se? Activity 3.11 pata karta hai.

Activity 3.11NCERT Activity 3.11 · p. 44

Dilute acid mein bubbles ki race

Tumhe chahiye

lagbhag ek hi size ke magnesium, aluminium, zinc, iron aur copper ke saaf tukde
paanch test tubes jinmein dilute hydrochloric acid ki barabar volume hai
ek thermometer
sandpaper

Pehle guess karo

Kis tube mein temperature sabse zyaada badhega?

Copper wali tubeIron wali tubeMagnesium wali tubeSaari tubes mein barabar

Har metal ko sandpaper se ragad kar saaf karo.
Acid ka shuruaati temperature note karo.
Har tube mein ek metal daalo. Dekho bubbles kitni tezi se bante hain, aur do minute baad har tube ka temperature padho.
Metals ko is hisaab se rank karo ki woh kitni tezi se react karte hain.

Table 3.5Bubbles ki race

Metal	Bubbles (koi nahi, kuch, bahut)	Temperature mein badhat (°C)
Magnesium
Aluminium
Zinc
Iron
Copper

Tumhari entries apne aap save hoti hain.

3/3Bubbling metals ko rank karti hai: Mg > Al > Zn > Fe, aur Cu react nahi karta.

Fig. 3.5Hydrogen ke bubbles dikhate hain ki kaun sa metal sabse tezi se react karta hai.

Dilute hydrochloric acid ki paanch test tubes ek rack mein khadi hain, jin par magnesium, aluminium, zinc, iron aur copper likha hai. Step 1 mein har tube mein abhi-abhi uska metal ka tukda daala gaya hai aur abhi kuch nahi hua. Step 2 mein hydrogen ke bubbles upar uthte hain: magnesium se bahut, aluminium aur zinc se kam, iron se thode aur copper se koi nahi, aur magnesium wali tube par warmest likha hai. Step 3 rack ke neeche ek arrow jodta hai jis par left mein most reactive aur right mein least reactive likha hai.

Tubes ko fizz aur garmi dono ke hisaab se rank karo, aur order ek hi aata hai: Mg > Al > Zn > Fe. Copper wali tube shaant aur thandi rehti hai: dilute hydrochloric acid copper ko kuch nahi karta. Magnesium ke liye:

\begin{aligned} M g + 2 H C l \\ \overset{}{\to} M g C l_{2} + H_{2} \end{aligned}

(3.18)

Aluminium, zinc aur iron milti-julti equations dete hain, aur aluminium chloride, zinc chloride aur iron(II) chloride banate hain.

3.2.4 Metals doosre Metal Salts ke Solutions ke saath kaise react karte hain?

Oxygen, water aur acids har metal ko rank nahi kar paaye, kyunki kuch metals unke saath bilkul react nahi karte. Ek tez test yeh hai ki ek metal ko doosre metal ke salt ke solution mein daalo aur dekho ki kya woh jagah badalte hain.

Activity 3.12NCERT Activity 3.12 · p. 44

Zinc aur copper sulphate ki mulaaqaat

Tumhe chahiye

zinc ki ek strip ya granule
saaf copper wire ke kuch tukde
copper(II) sulphate solution
zinc sulphate solution
do test tubes

Pehle guess karo

Kis tube mein badlaav dikhega?

Copper(II) sulphate mein zincZinc sulphate mein copperDono tubes meinKisi tube mein nahi

Zinc ko copper(II) sulphate solution mein daalo, aur copper ko zinc sulphate solution mein.
Dono tubes ko lagbhag 30 minute ke liye chhod do.
Metal surfaces aur har solution ka rang dekho. Tay karo ki kis tube mein reaction hua, aur tum kaise bata sakte ho.
Kisi bhi reaction ki balanced equation likho aur uska type batao.

3/3Har zinc atom ek copper ion ko do electrons deta hai: zinc oxidise hota hai, copper ions reduce hote hain.

Fig. 3.6Series mein upar wala metal neeche wale ko uske salt solution se bahar dhakel deta hai.NCERT Fig. 3.4 · p. 45

Do beakers. Left beaker mein blue copper sulphate solution aur ek grey zinc strip hai; right beaker mein colourless zinc sulphate solution aur ek copper strip hai. Step 1 mein abhi kuch nahi hua. Step 2 mein, tees minute baad, zinc strip copper ki bhoori coat se dhak gayi hai aur blue solution feeka ho gaya hai, jabki right beaker waisa hi hai aur us par no change likha hai. Step 3 ionic equation jodta hai: zinc atoms copper ions ko do electrons dete hain aur zinc ions ban jaate hain.

General rule yeh hai. Reactivity mein upar wala metal kisi compound mein neeche wale metal ko displace kar sakta hai, yaani uski jagah le sakta hai, chahe compound water mein ghula ho ya pighla hua ho. Ulta socho to yeh ek test ban jaata hai: jab bhi metal A, metal B ko B ke salt ke solution se bahar kheench le, to dono mein A zyaada reactive hai.

\begin{aligned} A + B ka salt \\ ⟶ A ka salt + B \end{aligned}

(3.19)

\begin{aligned} Z n + C u S O_{4} \\ \overset{}{\to} Z n S O_{4} + C u \end{aligned}

(3.20)

Yeh ek displacement reaction hai, woh type jo tumne Chapter 1 mein dekha tha. Yahi tab hota hai jab iron ki keel copper(II) sulphate solution mein chhod di jaaye: keel bhoori ho jaati hai aur blue solution dheere-dheere halka green iron(II) sulphate ban jaata hai. To iron bhi copper se zyaada reactive hai.

Example 3.3

Displacement results se metals ko rank karna

Chaar metals W, X, Y aur Z ko ek-ek karke teen salt solutions mein rakha gaya. Table dikhati hai ki kya hua.

Table 3.6Results

Metal	Zinc sulphate	Lead nitrate	Silver nitrate
W	koi badlaav nahi	displace hua	displace hua
X	koi badlaav nahi	koi badlaav nahi	koi badlaav nahi
Y	displace hua	displace hua	displace hua
Z	koi badlaav nahi	koi badlaav nahi	displace hua

(a) W, X, Y aur Z ko reactivity ke decreasing order mein lagao. (b) Inmein se kaun copper ho sakta hai?

Pehle khud try karo. Phir solution ek-ek step karke kholo.

3.2.5 Reactivity Series

In saare results ko Chapter 1 ke displacement experiments ke saath milao, to common metals ek hi list mein lag jaate hain, upar sabse zyaada reactive se neeche sabse kam reactive tak. Is list ko reactivity series (सक्रियता श्रेणी) kehte hain, ise activity series bhi kehte hain (Fig. 3.7).

1/3Common metals reactivity ke decreasing order mein.

Fig. 3.7Reactivity series, aur yeh kya predict karti hai.NCERT Table 3.2 · p. 45

Terah tiles top left se bottom right tak seedhiyon mein utarti hain: K, Na, Ca, Mg, Al, Zn, Fe, Pb, phir square brackets mein dashed outline wala H, phir Cu, Hg, Ag aur Au. Upar most reactive aur neeche least reactive likha hai. Step 2 hydrogen se ek line kheenchta hai: uske upar wale metals par dilute acids ke saath hydrogen dene ka mark hai aur neeche walon par nahi. Step 3 tiles ko is hisaab se chaar bands mein rangta hai ki har metal kaise extract hota hai: K se Al tak electrolysis, Zn se Pb tak carbon se reduction, Cu aur Hg ke liye sirf heating, aur Ag aur Au free roop mein milte hain.

Hydrogen metal nahi hai, lekin use series mein square brackets mein, lead aur copper ke beech rakha jaata hai. Isse upar wale metals dilute acids se hydrogen ko bahar dhakelte hain; neeche wale nahi kar sakte. Isiliye copper, mercury, silver aur gold dilute hydrochloric acid ke saath hydrogen nahi dete.

InteractiveDisplacement explorer

Ek interactive reactivity series. Learner potassium se gold tak gyaarah metals mein se ek, aur saat solutions mein se ek chunta hai: magnesium sulphate, zinc sulphate, iron(II) sulphate, lead nitrate, copper(II) sulphate, silver nitrate aur dilute hydrochloric acid. Series ki ladder chune gaye metal aur solution ke metal (ya hydrogen) ko highlight karti hai. Phir ek panel batata hai ki displacement hota hai ya nahi, balanced equation deta hai, aur batata hai ki tumhe kya dikhega, jaise bhoori copper coat aur feeka padta blue rang. Special cases samjhaaye gaye hain: potassium, sodium aur calcium uski jagah water ke saath react karte hain, aluminium apni oxide parat ki wajah se dheere shuru hota hai, aur lead jaldi ruk jaata hai kyunki ek insoluble coat ban jaati hai. Jab predict-first switch on ho, to ek score learner ke sahi predictions ginta hai.

Fig. 3.8Ek metal aur ek solution chuno aur predict karo ki reaction hoga ya nahi, phir equation padho aur dekho ki tumhe kya dikhega. Ladder dikhati hai ki dono metals reactivity series mein kahan hain.

Practice · 5 questions

Practice: reactivity (NCERT in-text questions, p. 46): answers ke saath

Short answerEasyNCERT in-text Questions p. 46, Q1
Chemicals ki ek dukaan potassium ke tukdon ko paraffin oil ki bottle mein rakhti hai. Kyun? Agar bottle ek nami wale kamre mein khuli chhod di jaaye to kya hoga?
Solution dikhao
AnswerOil hawa aur nami ko door rakhta hai; iske bina potassium oxidise ho jaata aur aag pakad sakta tha.
Potassium oxygen ke saath bahut tezi se aur water ke saath violently react karta hai, aur itni heat deta hai ki bani hui hydrogen aag pakad leti hai. Paraffin oil iske saath react nahi karta aur hawa aur nami ko door rakhta hai.
Nami wali hawa mein khuli bottle mein oil khule hue metal ko nahi bachaayega, jo jaldi dull ho jaayega aur water ke sampark mein aane par aag pakad sakta hai.
2
Short answerMediumNCERT in-text Questions p. 46, Q2
In reactions ki balanced equations likho.
1. Steam mein garam kiya gaya zinc
  Solution dikhao
  $Z n + H_{2} O (g)$ $\overset{}{\to} Z n O + H_{2}$
2. Garam water ke saath magnesium
  Solution dikhao
  $M g + 2 H_{2} O$ $\overset{}{\to} M g (O H)_{2} + H_{2}$
3. Thande water ke saath sodium
  Solution dikhao
  $2 N a + 2 H_{2} O$ $\overset{}{\to} 2 N a O H + H_{2}$
3
Short answerMediumNCERT in-text Questions p. 46, Q3
Chaar metals P, Q, R aur S ko ek-ek karke zinc sulphate, iron(II) sulphate, copper(II) sulphate aur silver nitrate ke solutions mein daala gaya. P ne iron, copper aur silver ko displace kiya; Q ne sirf silver ko; R ne chaaron metals ko; S ne copper aur silver ko.
1. Chaaron metals mein kaun reactivity series mein sabse upar hai?
  Solution dikhao
  AnswerR
  R zinc, iron, copper aur silver ko displace karta hai, isliye yeh in sabse upar hai.
2. Agar S ko copper(II) sulphate solution mein daala jaaye to tumhe kya dikhega?
  Solution dikhao
  AnswerS par bhoori copper coat, aur blue rang feeka padta hua
  Table dikhati hai ki S copper ko displace karta hai, isliye copper S par laal-bhoori coat ke roop mein jam jaayega aur blue copper ions use ho jaayenge.
3. (c)
  P, Q, R aur S ko reactivity ke decreasing order mein lagao.
  R
  S
  P
  Q
  Answer dekho
  Answer
  R
  P
  S
  Q
  R chaaron ko displace karta hai; P zinc ke alawa sabko; S sirf copper aur silver ko; Q sirf silver ko.
Short answerEasyNCERT in-text Questions p. 46, Q4
Jab koi reactive metal dilute sulphuric acid mein daala jaata hai to kaun si gas nikalti hai, aur tum uska test kaise karoge? Zinc aur dilute sulphuric acid ki balanced equation likho.
Solution dikhao
AnswerHydrogen; yeh pop ki awaaz ke saath jalti hai.
Gas hydrogen hai. Tube ke munh par jalti teeli rakhne se yeh 'pop' ki awaaz ke saath jalti hai.
Zinc ke liye: $Z n + H_{2} S O_{4}$ $\overset{}{\to} Z n S O_{4} + H_{2}$
Short answerMediumNCERT in-text Questions p. 46, Q5
Agar magnesium ki strip halke green iron(II) sulphate solution mein rakhi jaaye to tumhe kya dikhega? Equation likho.
Solution dikhao
AnswerMagnesium par iron ki gehri parat jam jaati hai; green rang feeka padta hai.
Magnesium iron se upar hai, isliye yeh iron ko displace karta hai. Strip par iron ki gehri grey ya kaali layer banti hai aur colourless magnesium sulphate banne se halka green rang feeka pad jaata hai.
Equation: $M g + F e S O_{4}$ $\overset{}{\to} M g S O_{4} + F e$

3.3 Metals aur Non-metals kaise React karte hain?

Metals react hi kyun karte hain, aur kuch doosron se kahin zyaada utaavlepan se kyun react karte hain? Class 9 se yaad karo ki noble gases (helium, neon, argon …) mushkil se react karti hain. Unka outermost shell bhara hota hai: helium ke liye do electrons aur baakiyon ke liye aath. Doosre elements aise tareekon se react karte hain jinse unhe bhi aisa bhara outer shell mil jaaye. Table 3.7 kuch metals aur non-metals ke shells dikhata hai.

Table 3.7Kuch elements ke shells mein electrons

Element	Atomic number	K	L	M	N
		Shell mein electrons
Neon (noble gas)	10	2	8	–	–
Argon (noble gas)	18	2	8	8	–
Sodium (metal)	11	2	8	1	–
Magnesium (metal)	12	2	8	2	–
Potassium (metal)	19	2	8	8	1
Calcium (metal)	20	2	8	8	2
Oxygen (non-metal)	8	2	6	–	–
Fluorine (non-metal)	9	2	7	–	–
Sulphur (non-metal)	16	2	8	6	–
Chlorine (non-metal)	17	2	8	7	–

Sodium 2, 8, 1 hai: uske teesre shell mein ek akela electron hai. Us electron ko jaane do, to neeche wala shell, jismein pehle se poore aath hain, particle ka bahari hissa ban jaata hai. Ab charges gino: nucleus mein 11 protons lekin sirf 10 electrons. Ek positive charge bach jaata hai, isliye particle ek positive ion hai, sodium cation:

\underset{2, 8, 1}{N a} ⟶ \underset{2, 8}{N a^{+}} + e^{-}

(3.21)

Chlorine, 2, 8, 7, ulti position mein hai: uske outer shell mein aath poore hone ke liye bas ek electron kam hai. Woh electron mil jaaye to uske 17 protons ke saamne 18 electrons hote hain, aur ek extra negative charge bachta hai. Ab yeh chloride anion hai:

\underset{2, 8, 7}{C l} + e^{-} ⟶ \underset{2, 8, 8}{C l^{-}}

(3.22)

Dono ko saath rakho to har ek doosre ki problem solve kar deta hai: jo electron sodium de sakta hai, wahi chlorine ke paas kam hai (Fig. 3.9). Bane hue ions par opposite charges hote hain aur woh ek doosre ko zor se kheenchte hain, aur yahi electrostatic kheench sodium chloride ko jode rakhta hai. Isliye namak ka ek daana alag-alag 'NaCl molecules' ka dher nahi hai. Yeh $N a^{+}$ aur $C l^{-}$ ions ka ek bahut bada, tarteeb se laga stack hai, jismein har ion apne padosiyon se jakda hua hai.

3/3Ab dono ka outer shell bhara hai: $N a^{+}$ aur $C l^{-}$ ek doosre ko attract karte hain.

Fig. 3.9Sodium chloride ek electron ke transfer se banta hai.NCERT Fig. 3.5 · p. 47

Electron-dot diagrams. Step 1: ek sodium atom jiska ek outer electron cross ki tarah bana hai, us par 2, 8, 1 likha hai, aur ek chlorine atom jiske saat outer electrons dots ki tarah bane hain, us par 2, 8, 7 likha hai. Step 2: cross sodium se ek curved arrow ke saath chal kar chlorine atom ka khaali gap bhar deta hai. Step 3: ek arrow products tak le jaata hai: square brackets mein plus charge wala sodium ion, jis par 2, 8 likha hai, aur brackets mein aath outer electrons aur minus charge wala chloride ion, jis par 2, 8, 8 likha hai; dono ions ek doosre ko attract karte hain.

Fig. 3.9 mein sirf outer-shell electrons bane hain, symbol ke charon taraf dots ya crosses ki tarah. Aisi drawing electron-dot structure kehlaati hai. Crosses metal ke electrons ko mark karte hain taaki tum dekh sako ki woh kahan jaate hain.

Magnesium (2, 8, 2) ke paas dene ke liye do electrons hain, lekin ek chlorine atom sirf ek le sakta hai. Isliye ek magnesium atom do chlorine atoms ke saath react karta hai (Fig. 3.10). Magnesium chloride, $M g C l_{2}$ , $M g^{2 +}$ cations aur unse dugne $C l^{-}$ anions se bana hai.

\underset{2, 8, 2}{M g} ⟶ \underset{2, 8}{M g^{2 +}} + 2 e^{-}

(3.23)

3/3Ek $M g^{2 +}$ ion aur do $C l^{-}$ ions milkar magnesium chloride banate hain.

Fig. 3.10Ek magnesium atom do chlorine atoms mein se har ek ko ek electron deta hai.NCERT Fig. 3.6 · p. 48

Electron-dot diagrams. Step 1: ek magnesium atom jiske do outer electrons crosses ki tarah bane hain, us par 2, 8, 2 likha hai, do chlorine atoms ke beech mein hai jinke paas saat-saat dots aur magnesium ki taraf ek gap hai. Step 2: curved arrows ek-ek cross har chlorine atom tak le jaate hain. Step 3: ek arrow neeche products tak le jaata hai: brackets mein 2+ charge wala magnesium ion, brackets mein do chloride ions ke beech, jinmein se har ek ke paas aath outer electrons aur minus charge hai; ab har ion ka outer shell bhara hai.

Jab bhi koi metal electrons non-metal ko de deta hai, to product ek ionic compound (आयनिक यौगिक) hota hai, jise electrovalent compound bhi kehte hain.

Definition

Ionic (electrovalent) compound

Positive aur negative ions ka compound jo electrostatic attraction se juda rehta hai, aur tab banta hai jab metal non-metal ko electrons transfer karta hai.

ExampleSodium chloride, magnesium chloride aur calcium oxide.

Example 3.4

Electron transfer se potassium sulphide

Dikhao ki potassium (atomic number 19) aur sulphur (atomic number 16) potassium sulphide kaise banate hain. Ions ke naam batao aur formula likho.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Oxides bhi isi tarah banaaye jaate hain (Fig. 3.11). Oxygen (2, 6) ko do electrons chahiye. Ek lithium atom (2, 1) sirf ek de sakta hai, isliye do lithium atoms chahiye aur formula $L i_{2} O$ hai; ek calcium atom apne dono outer electrons de deta hai, isliye calcium oxide bas $C a O$ hai.

Fig. 3.11Do lithium atoms, ya ek calcium atom, woh do electrons dete hain jo oxygen atom ko chahiye.

Electron-dot diagrams ki do rows. Upar wali row: do lithium atoms, jinmein se har ek ka ek outer electron cross ki tarah bana hai, apne electrons curved arrows ke saath chhe dots wale oxygen atom ko bhejte hain; products hain brackets mein ek-ek plus charge wale do lithium ions aur brackets mein aath outer electrons aur 2 minus charge wala oxide ion. Neeche wali row: do crosses wala ek calcium atom dono electrons oxygen atom ko bhejta hai; products hain 2 plus charge wala calcium ion aur 2 minus charge wala oxide ion.

Compare

Metals aur non-metals: chemical behaviour

Metals

Basic oxides banate hain (kuch amphoteric hote hain)
Electrons kho kar positive ions banate hain
Hydrogen se upar wale dilute acids ke saath hydrogen dete hain
Aksar reducing agents ki tarah kaam karte hain (electrons dete hain)

Non-metals

Acidic ya neutral oxides banate hain (CO neutral hai)
Electrons le kar negative ions banate hain
Dilute acids ke saath hydrogen nahi dete
Hydrogen ke saath judkar $H_{2} S$ aur $N H_{3}$ jaise hydrides banate hain

3.3.1 Ionic Compounds ki Properties

Activity 3.13NCERT Activity 3.13 · p. 48

Kuch salts ko test karna

Tumhe chahiye

khaane ka namak (sodium chloride)
potassium chloride
calcium chloride
ek metal spatula aur ek burner
water aur kerosene ke chhote beakers
Activity 3.6 wala conduction tester, electrodes ke liye do saaf iron ki keelon ke saath

Pehle guess karo

Common salt kis liquid mein ghulega?

KeroseneWaterDono meinKisi mein nahi

Har salt ki state aur woh kaisa dikhta hai, note karo.
Ek salt ka thoda sa hissa spatula par flame mein garam karo. Note karo ki flame ka rang badalta hai ya nahi aur salt pighalta hai ya nahi. Baaki ke saath dohrao.
Har salt ki ek chutki ek beaker mein water ke saath aur doosre mein kerosene ke saath hilaao.
Tester ke dono keel wale electrodes ko har water solution mein dubaao, unhe alag rakhte hue, aur bulb ko dekho.

Ions in sab observations ko samjhaate hain:

Hard lekin brittle solids. Opposite charge wale ions ke beech strong attraction crystals ko hard banata hai. Ek tez chot ions ki ek layer ko agli layer ke muqaable khiska deti hai, like charges aamne-saamne aa kar repel karte hain, aur crystal toot jaata hai.
High melting aur boiling points. Crystal ko pighlaane ke liye ions ko ek doosre se hila kar alag karna padta hai, aur unka strong attraction ismein bahut energy kharch karwata hai (Table 3.8).
Water mein soluble, kerosene ya petrol mein nahi. Water molecules ions ko alag kheench sakte hain; kerosene aur petrol nahi kar sakte.
Pighle hue ya ghule hue roop mein electricity conduct karte hain, lekin solid roop mein nahi. Current ke liye aise charged particles chahiye jo chal sakein. Solid mein ions apni jagah jakde rehte hain; pighalne ya ghulne par woh azaad hokar opposite charge wale electrodes ki taraf jaa sakte hain (Fig. 3.12).

Table 3.8Ionic compounds molecular substances se kahin zyaada temperature par pighalte aur boil hote hain

Substance	Type	Pighalta hai (°C)	Boil hota hai (°C)
Sodium chloride	ionic	801	1465
Potassium chloride	ionic	770	1420
Magnesium oxide	ionic	2852	3600
Water	molecular	0	100
Ethanol	molecular	−114	78
Naphthalene	molecular	80	218

3/3Ghule hue ions bhi chalne ke liye azaad hote hain, isliye solution conduct karta hai.

Fig. 3.12Current le jaane ke liye ions ka chalne ke liye azaad hona zaroori hai.NCERT Fig. 3.8 · p. 48

Ek cell, ek bulb aur plus aur minus mark kiye do electrodes, ek ionic compound ke sample mein dube hain jo plus aur minus ions ki tarah bana hai. Step 1 mein sample solid hai: ions ek saaf grid mein baithe hain, hil nahi sakte, aur bulb andhera hai. Step 2 mein sample flame par pighla hua hai: ions bikhre hue hain aur chalte hain, positive ions negative electrode ki taraf aur negative ions positive ki taraf, aur bulb jalta hai. Step 3 mein compound water mein ghula hai: ions phaile hue hain aur chal rahe hain, aur bulb jalta hai.

Practice · 2 questions

Practice: ionic compounds (NCERT in-text questions, p. 49): answers ke saath

1
DiagramMediumNCERT in-text Questions p. 49, Q1
Potassium ka atomic number 19, fluorine ka 9 aur calcium ka 20 hai.
1. Potassium, fluorine aur calcium ke electron-dot structures banao.
  Solution dikhao
  K (2, 8, 8, 1) ke paas ek outer electron hai: K ke saath ek cross. F (2, 7) ke paas saat hain: F ke saath dots ke teen pairs aur ek akela dot. Ca (2, 8, 8, 2) ke paas do hain: Ca ke saath do crosses.
2. Electrons ke transfer se potassium fluoride aur calcium fluoride ka banna dikhao.
  Solution dikhao
  Potassium fluoride: potassium ka akela cross fluorine ke paas wale gap mein chala jaata hai. Tumhe [K]⁺ aur [F]⁻ milte hain, fluoride ion ke paas aath outer electrons (saat dots aur ek cross) hote hain. Formula $K F$ .
  Calcium fluoride: ek fluorine atom sirf ek electron le sakta hai, isliye calcium ke do crosses do alag fluorine atoms par jaate hain, bilkul Fig. 3.10 ki tarah. Tumhe [Ca]²⁺ aur do [F]⁻ ions milte hain. Formula $C a F_{2}$ .
3. Har compound mein maujood ions ke naam batao.
  Solution dikhao
  AnswerKF: K⁺ aur F⁻. CaF₂: Ca²⁺ aur F⁻.
  Potassium fluoride mein $K^{+}$ aur $F^{-}$ 1 : 1 ratio mein hain. Calcium fluoride mein $C a^{2 +}$ aur $F^{-}$ 1 : 2 ratio mein hain.
Short answerMediumNCERT in-text Questions p. 49, Q2
Furnaces ke andar magnesium oxide ki eenton ki lining hoti hai. Iske particles ke basis par samjhao ki magnesium oxide itne high temperatures kaise jhel leta hai.
Solution dikhao
AnswerMg²⁺ aur O²⁻ ions ke beech ke strong attraction ko todne ke liye bahut zyaada energy chahiye.
Magnesium oxide ek ionic compound hai: $M g^{2 +}$ aur $O^{2 -}$ ions ka bahut bada stack jo strong electrostatic attraction se juda hai. Pighalne ka matlab hai is regular stack ko todna, jiske liye bahut zyaada energy chahiye. Double charge wale ions mein attraction khaas taur par strong hota hai, isliye magnesium oxide lagbhag 2850 °C par hi pighalta hai.

3.4 Metals kahan milte hain

Odisha ki pahaadiyon se khoda gaya bauxite, Chhattisgarh ka haematite aur Rajasthan ka zinc ore, sab Earth ke crust se aate hain, jo hamare use hone wale metals ka main bhandaar hai. Samudra ek doosra, chhota bhandaar hai, jismein sodium chloride aur magnesium chloride jaise salts ghule hue hain. Crust mein nature se bana koi bhi element ya compound ek mineral (खनिज) hai. Jab kisi mineral mein metal itna zyaada ho ki metal nikaalna faaydemand ho, to use ore (अयस्क) kehte hain.

Definition

Ore

Aisa mineral jisse metal faayde ke saath extract kiya ja sake.

ExampleBauxite aluminium ka ore hai; haematite, $F e_{2} O_{3}$ , iron ka ek ore hai. Har ore ek mineral hai, lekin har mineral ore nahi hai.

3.4.1 Metals ka Extraction

Reactivity series mein metal ki jagah batati hai ki nature use kaise store karta hai (Table 3.9). Unreactive metals laakhon saalon se kisi ke saath jude bina bache rahe hain; reactive metals bahut pehle doosre elements ke saath jud gaye. Ores mein oxides khaas taur par common hain, kyunki oxygen reactive bhi hai aur bahut maatra mein bhi hai.

Table 3.9Metal ki reactivity kaise tay karti hai ki woh kis roop mein milta hai

Series ka hissa	Metals kis roop mein milte hain	Examples
Neeche (least reactive)	Aksar free (native) roop mein, khud metal ki tarah; copper aur silver sulphide ya oxide ores ke roop mein bhi	gold, silver, platinum, copper
Beech mein	Combined; inke ores aam taur par oxides, sulphides ya carbonates hote hain	zinc, iron, lead
Upar (most reactive)	Kabhi free nahi; hamesha combined	potassium, sodium, calcium, magnesium, aluminium

Extraction bhi isi teen hisson wale batwaare ko follow karta hai: kam reactivity wale metals ke liye ek tareeka, beech walon ke liye ek aur upar walon ke liye ek (Fig. 3.7 ka teesra step). Metal ko uske ore se nikaalna aur purify karna metallurgy (धातुकर्म) kehlaata hai. Fig. 3.13 dikhata hai ki ore kis raaste se guzarta hai.

4/4Hg, Cu: sulphide ko hawa mein garam karna kaafi hai. Phir har metal refine hota hai.

Fig. 3.13Ore se pure metal tak: tareeka reactivity par depend karta hai.NCERT Fig. 3.10 · p. 50

Ek flow chart. Step 1: ore ka box concentration tak jaata hai, jahan gangue hataya jaata hai. Step 2 sodium jaise sabse reactive metals ki left branch highlight karta hai: pighle compound ka electrolysis metal deta hai. Step 3 zinc jaise metals ki middle branch highlight karta hai: sulphide ore ko roast, ya carbonate ore ko calcine karke oxide banaya jaata hai, jise phir carbon se reduce kiya jaata hai. Step 4 mercury jaise kam reactivity wale metals ki right branch highlight karta hai: sulphide ko hawa mein garam karna kaafi hai. Teenon branches metal par khatam hoti hain, jise phir refine karke pure metal milta hai.

3.4.2 Ores ka Enrichment

Pakaane se pehle chawal aur dal se chhote patthar aur bhoosa chun kar nikaala jaata hai. Ore ko bhi yahi treatment chahiye, bahut bade paimaane par. Khaan se nikle patthar mein bahut si mitti, ret aur patthar hote hain, jinhe gangue (गैंग) kehte hain, aur koi bhi metal extract karne se pehle inhe hatana padta hai. Is safaai ko ore ka concentration ya enrichment kehte hain. Trick hamesha yeh hoti hai ki koi aisi property, physical ya chemical, use karo jismein ore aur gangue alag hon.

Jaise, bhaari ore particles ko paani ki dhaar mein halki ret se dho kar alag kiya ja sakta hai. Magnetic iron ore ko non-magnetic patthar se magnet ke zariye chuna ja sakta hai. Sulphide ores aksar froth flotation se alag kiye jaate hain: ore particles tel jaise jhaag se chipak kar upar tair jaate hain, jabki gangue neeche baith jaata hai.

3.4.3 Activity Series mein Neeche wale Metals ko Extract karna

Series ke neeche ke paas metals oxygen ko itni kamzori se pakadte hain ki sirf heat se hi woh azaad ho jaate hain. Mercury cinnabar, yaani mercury(II) sulphide, se aata hai. Cinnabar ko hawa mein roast karo to uska sulphur sulphur dioxide ban kar nikal jaata hai, aur mercury(II) oxide bachta hai; garam karte raho to oxide khud mercury aur oxygen mein toot jaata hai:

\begin{aligned} 2 H g S + 3 O_{2} \\ \overset{h e a t}{\to} 2 H g O \\ + 2 S O_{2} \end{aligned}

(3.24)

\begin{aligned} 2 H g O \\ \overset{h e a t}{\to} 2 H g + O_{2} \end{aligned}

(3.25)

Copper glance, $C u_{2} S$ , se bhi copper isi tarah milta hai. Sulphide ka kuch hissa hawa mein garam karke copper(I) oxide banaya jaata hai, jo phir baaki sulphide ke saath react karta hai:

\begin{aligned} 2 C u_{2} S + 3 O_{2} \\ \overset{h e a t}{\to} 2 C u_{2} O \\ + 2 S O_{2} \end{aligned}

(3.26)

\begin{aligned} 2 C u_{2} O + C u_{2} S \\ \overset{h e a t}{\to} 6 C u \\ + S O_{2} \end{aligned}

(3.27)

3.4.4 Activity Series ke Beech wale Metals ko Extract karna

Zinc, iron, lead aur copper series ke beech mein hain aur aam taur par sulphides ya carbonates ke roop mein khode jaate hain. Chemists oxide se shuru karna pasand karte hain, jise reduce karna kahin aasaan hai, isliye pehla kaam ore ko badalna hai:

Roasting (भर्जन): sulphide ore ko bahut saari hawa mein tez garam karna.
Calcination (निस्तापन): carbonate ore ko kam ya bilkul nahi hawa mein tez garam karna.

Roasting

\begin{aligned} 2 Z n S + 3 O_{2} \\ \overset{h e a t}{\to} 2 Z n O \\ + 2 S O_{2} \end{aligned}

(3.28)

Calcination

\begin{aligned} Z n C O_{3} \\ \overset{h e a t}{\to} Z n O + C O_{2} \end{aligned}

(3.29)

Phir oxide ko ek reducing agent ke saath garam kiya jaata hai, aksar coke ke roop mein carbon, jo oxygen ko le jaata hai. Chapter 1 se yaad karo ki oxygen hatana reduction hai. Kisi metal ko uske compound se nikaalna, asal mein, ek reduction hi hai.

\begin{aligned} Z n O + C \\ \overset{}{\to} Z n + C O \end{aligned}

(3.30)

Example 3.5

Do alag ores se lead

Lead zyaadatar galena, yaani lead(II) sulphide ( $P b S$ ), ke roop mein khoda jaata hai, aur kabhi-kabhi cerussite, yaani lead(II) carbonate ( $P b C O_{3}$ ), ke roop mein. Har ore ke liye us step ka naam batao jo use lead(II) oxide mein badalta hai aur uski equation likho. Phir dikhao ki oxide se lead kaise milta hai.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Carbon akela oxygen chor nahi hai. Series mein upar wala metal, jaise sodium, calcium ya aluminium, neeche wale metal ke oxide se oxygen chheen sakta hai. Jaise, manganese dioxide ko aluminium powder ke saath garam karne se manganese milta hai:

\begin{aligned} 3 M n O_{2} + 4 A l \\ \overset{}{\to} 3 M n + 2 A l_{2} O_{3} \\ + h e a t \end{aligned}

(3.31)

Yahan aluminium oxygen leta hai, isliye woh oxidise hota hai, jabki manganese dioxide oxygen khota hai aur reduce hota hai.

Is tarah ke reactions itni tezi se heat dete hain ki azaad hua metal liquid ban kar nikalta hai. Sabse mashhoor hai iron(III) oxide aur aluminium ka thermit reaction, jo rails ko weld karne aur toote machine parts ko wahin theek karne ke liye safed-garam pighla iron deta hai:

Thermit reaction

\begin{aligned} F e_{2} O_{3} + 2 A l \\ \overset{}{\to} 2 F e + A l_{2} O_{3} \\ + h e a t \end{aligned}

(3.32)

Chromium metal bhi isi tarah banta hai, chromium(III) oxide ko aluminium powder ke saath garam karke:

\begin{aligned} C r_{2} O_{3} + 2 A l \\ \overset{}{\to} 2 C r + A l_{2} O_{3} \\ + h e a t \end{aligned}

(3.33)

Example 3.6

Kaun oxidise hota hai, kaun reduce?

(3.33) ka reaction dekho. (a) Kaun sa substance oxidise hota hai aur kaun sa reduce? (b) Aluminium yeh kaam kyun kar sakta hai? (c) Chromium liquid ban kar kyun nikalta hai?

Pehle khud try karo. Phir solution ek-ek step karke kholo.

3.4.5 Activity Series mein Upar wale Metals ko Extract karna

Sodium oxide, magnesium oxide ya aluminium oxide ko carbon ke saath garam karke dekho, kuch nahi hota: yeh metals oxygen ko carbon se zyaada mazbooti se pakadte hain. Inhe electrolytic reduction se nikaala jaata hai, jismein pighle compound se guzarta electric current reduction karta hai.

Sodium, magnesium aur calcium ke liye shuruaati material pighla hua chloride hai. Jaise-jaise current pighle material se guzarta hai, metal cathode (negative electrode) par jamta hai aur chlorine gas anode (positive electrode) par nikalti hai. Pighle sodium chloride ke saath:

Cathode par

N a^{+} + e^{-} \overset{}{\to} N a

(3.34)

Anode par

2 C l^{-} \overset{}{\to} C l_{2} + 2 e^{-}

(3.35)

Cathode par sodium ions electrons lete hain, isliye woh reduce hote hain. Aluminium bhi isi tarah, aluminium oxide ka electrolysis karke milta hai. Compound pighla hua hona chahiye, water mein ghula hua nahi: water solution mein cathode par sodium ki jagah water se hydrogen nikal jaati.

3.4.6 Metals ki Refining

Electric wiring ke liye copper bahut zyaada pure hona chahiye, kyunki thodi si impurity bhi uska resistance badha deti hai. Furnace se seedha nikla metal itna pure nahi hota, isliye use refine kiya jaata hai. Sabse zyaada use hone wala tareeka electrolytic refining (विद्युत-अपघटनी परिष्करण) hai, jo copper, nickel, zinc, tin, silver, gold aur doosron par lagaaya jaata hai.

Copper ko lo (Fig. 3.14). Impure metal ka ek mota slab anode ki tarah joda jaata hai, pure copper ki ek patli sheet cathode ki tarah, aur dono acidified copper(II) sulphate solution mein dube hote hain. Jaise-jaise current behta hai, copper atoms anode se $C u^{2 +}$ ions ban kar nikalte hain, solution paar karte hain, aur cathode par fresh, pure metal ki tarah jam jaate hain:

Anode par

C u \overset{}{\to} C u^{2 +} + 2 e^{-}

(3.36)

Cathode par

C u^{2 +} + 2 e^{-} \overset{}{\to} C u

(3.37)

Impurities alag ho jaati hain. Jo ghul jaati hain woh solution mein reh jaati hain; jo nahi ghulti, jinmein aksar keemti silver aur gold bhi hote hain, woh anode ke neeche tank ke farsh par anode mud ban kar gir jaati hain.

Definition

Electrolytic refining

Electrolysis se metal ko purify karna, jismein impure metal anode hota hai, pure metal ki patli sheet cathode hoti hai, aur us metal ke salt ka solution electrolyte hota hai.

ExampleImpure copper ko acidified copper(II) sulphate solution mein refine kiya jaata hai.

3/3Anode patla hota hai, cathode mota hota hai, aur insoluble impurities anode mud ke roop mein ikatthi hoti hain.

Fig. 3.14Copper ki electrolytic refining.NCERT Fig. 3.12 · p. 52

Blue acidified copper sulphate solution ka ek tank, left mein pure copper ka patla cathode jo power supply ke negative terminal se juda hai, aur right mein impure copper ka mota anode jo positive terminal se juda hai. Step 1 mein kuch nahi behta. Step 2 mein copper ions, jin par Cu 2 plus likha hai, anode se solution paar karke cathode tak jaate hain. Step 3 mein anode patla ho gaya hai, cathode mota, aur anode ke neeche tank ke farsh par anode mud ka dher pada hai.

Quick check

4 mein se 1

Har shuruaati material ko sahi treatment se match karo.

Left mein koi item tap karo, phir right mein uska match.

Answer dekho

Answer

Gold ke dhele : free milta hai; bas alag karo
Zinc blende, ZnS : roast karo, phir carbon se reduce karo
Pighla sodium chloride : electrolysis
Impure copper : electrolytic refining

Gold native roop mein milta hai; beech wale metal ke sulphide ko roast karke phir carbon se reduce kiya jaata hai; upar wale metal ko uske melt ka electrolysis chahiye; impure copper ko anode bana kar purify kiya jaata hai.

Practice · 3 questions

Practice: occurrence aur extraction (NCERT in-text questions, p. 53): answers ke saath

1
Short answerEasyNCERT in-text Questions p. 53, Q1
Ek company ko aluminium compounds wale do deposits milte hain. Ek aluminium oxide se bhara bauxite hai. Doosra ek clay hai jismein bahut kam aluminium hai, jise nikaalne mein uski keemat se zyaada kharcha aayega.
1. Kaun sa deposit ore hai, aur kaun sa sirf mineral? Samjhao.
  Solution dikhao
  AnswerBauxite ore hai; clay mineral hai lekin ore nahi.
  Dono minerals hain, kyunki nature ne unhe Earth ke crust mein banaya. Sirf bauxite ore hai, kyunki usse aluminium faayde ke saath extract kiya ja sakta hai.
2. Bauxite ret aur laal mitti ke saath mila hai. Inhe kya kehte hain, aur inhe pehle kyun hataya jaata hai?
  Solution dikhao
  AnswerGangue; yeh energy barbaad karega aur metal ko ganda karega.
  Bekaar ret aur mitti gangue hai. Inhe pehle (concentration mein) hataya jaata hai taaki inhe process karne mein energy barbaad na ho aur yeh metal mein impurities na ban jaayein.
Short answerEasyNCERT in-text Questions p. 53, Q2
Do metals ke naam batao jo ek prospector ko pure metal ke dhelon ke roop mein mil sakte hain, aur samjhao ki woh free kyun milte hain.
Solution dikhao
AnswerGold aur platinum (silver, copper bhi).
Gold aur platinum (aur kabhi-kabhi silver aur copper) free milte hain. Woh itne unreactive hain ki geological time mein bhi oxygen, sulphur ya doosre elements ke saath nahi jude.
Short answerEasyNCERT in-text Questions p. 53, Q3
Ek smelter mein zinc oxide ko coke ke saath garam kiya jaata hai aur zinc metal milta hai. Zinc oxide mein kis type ka chemical change hota hai, aur coke kya kaam karta hai?
Solution dikhao
AnswerReduction; coke reducing agent hai.
Zinc oxide apni oxygen kho deta hai, isliye woh reduce hota hai: $Z n O + C$ $\overset{}{\to} Z n + C O$ . Coke (carbon) oxygen le leta hai aur khud oxidise hokar carbon monoxide ban jaata hai; yeh reducing agent ka kaam karta hai.

3.5 Corrosion

Chamakdaar metal ko kaafi der hawa mein chhod do to uski surface badal jaati hai. Chapter 1 mein tumne teen examples dekhe the (Table 3.10). Aas-paas ki hawa, nami ya chemicals se metal ke dheere-dheere ghisne ko corrosion (संक्षारण) kehte hain.

Table 3.10Corrosion ke teen jaane-pehchaane types

Metal	Kya dikhta hai	Kya banta hai	Kis wajah se
Silver	Gehne aur plates kaale pad jaate hain	silver sulphide	hawa mein sulphur compounds
Copper	Bhoori surface green ho jaati hai, jaise purane gumbadon aur statues par	basic copper carbonate	hawa mein nami wala carbon dioxide
Iron	Bhoori, papdi jaisi coating	rust, ek hydrated iron(III) oxide	oxygen aur water dono saath mein

Rusting sabse mehenga type hai: bridges, ships, cars aur railway coaches har saal iske kaaran iron kho dete hain. Activity 3.14 pata karta hai ki iron ko rust lagne ke liye kya chahiye.

Activity 3.14NCERT Activity 3.14 · p. 53

Iron ko rust lagne ke liye kya chahiye?

Tumhe chahiye

teen saaf iron ki keelein
dhakkan wale teen chhote glass jars
nal ka water
water jise ubaal kar thanda kiya gaya ho
thoda sa cooking oil
do ya teen silica-gel sachets (shoe box ya dawai ki bottle se)

Pehle guess karo

Kis jar mein keel ko rust lagega?

B: oil ke neeche uble water meinC: silica gel ke saath sookhi hawa meinA: aadhi nal ke water meinTeenon mein, barabar

Jar A: ek keel ko thode nal ke water mein khada karo taaki woh aadhi dhaki rahe. Dhakkan band karo.
Jar B: ek keel ko aise water se dhako jise ghuli hawa nikaalne ke liye ubaala gaya aur phir thanda kiya gaya. Hawa ko bahar rakhne ke liye upar oil ki patli layer daalo. Dhakkan band karo.
Jar C: ek keel ko silica-gel sachets ke saath sookhe jar mein rakho, jo nami sokh lete hain. Dhakkan band karo.
Jars ko chaar-paanch din ke liye chhod do, phir keelon ko compare karo.

3/3Iron ko rust tabhi lagta hai jab oxygen (hawa) aur water dono maujood hon.

Fig. 3.15Rusting ke liye hawa aur water dono chahiye.NCERT Fig. 3.13 · p. 53

Teen band glass jars, A, B aur C, har ek mein iron ki ek keel. Jar A mein keel ke neeche wale hisse ke charon taraf thoda nal ka water hai. Jar B oil ki patli layer ke neeche uble water se bhara hai. Jar C sookha hai, farsh par chhote silica-gel sachets ke saath. Step 1 mein, day 0 par, teenon keelein saaf aur grey hain. Step 2 mein, day 5 par, jar A ki keel bhoore rust se dhaki hai, jabki B aur C ki keelein abhi bhi saaf hain. Step 3 batata hai ki har jar kya deta hai: A mein hawa aur water, B mein sirf water, C mein sirf hawa.

To jo bhi cheez hawa ya water ko iron se door rakhe, woh rusting ko dheema karti hai.

3.5.1 Corrosion se Bachaav

Rust ko harane ke do tareeke hain. Ek hai aisi barrier jo hawa aur water ko iron se door rakhe: paint, oil, grease, ya chromium (chrome plating) ya zinc (galvanising) ki plating. Doosra hai alloy bana kar iron ko hi badal dena. Anodising, jo tumne pehle dekha, aluminium ko isi tarah ki barrier se bachaata hai. Paint, oil aur grease tabhi tak madad karte hain jab tak layer tooti na ho.

Galvanisation (यशदलेपन) iron ya steel par zinc ki patli coat chadhata hai; corrugated roofing sheets, baaltiyan aur fence wire aam taur par galvanised hote hain. Ab hairaani ki baat: jahan zinc mein scratch iron tak pahunch jaaye, wahan bhi neeche ka iron rust nahi hota. Zinc iron se zyaada reactive hai, isliye jahan dono metals hawa aur water se milte hain, wahan pehle zinc par attack hota hai aur iron bach jaata hai (Fig. 3.16).

Definition

Galvanisation

Iron ya steel par zinc ki patli coat chadha kar use rusting se bachaana.

ExampleGalvanised iron (GI) roofing sheets aur baaltiyan.

4/4Tin iron se kam reactive hai, isliye khula iron rust ho jaata hai.

Fig. 3.16Zinc scratch ke baad bhi iron ko bachaata hai; tin nahi bachaata.

Do cut-away views aamne-saamne: left mein zinc coating wala iron, right mein tin coating wala iron. Step 1 mein dono coatings poori hain. Step 2 mein ek scratch har coating ko kaat kar iron tak pahunchta hai, aur har scratch mein paani ki ek boond hai. Step 3 mein, zinc wali side par, scratch ke paas ka zinc corrode hokar khatam hota hai jabki neeche ka iron saaf rehta hai, jis par zinc corrodes first likha hai. Step 4 mein, tin wali side par, scratch mein bhoora rust badhta hai aur tin ke neeche phailta hai, jis par iron rusts likha hai.

Tin-plated steel ulta behave karta hai. Tin iron se kam reactive hai, isliye yeh tabhi tak bachaata hai jab tak tooti na ho; scratch se neeche ka iron rust ho jaata hai. Phir bhi food cans ke liye tin chuna jaata hai kyunki yeh unreactive aur harmless hai, jabki zinc acidic khaane ke saath react karta.

Tum jo bhi iron ki cheez dekhte ho, woh lagbhag hamesha asal mein ek alloy hoti hai. Pure iron zyaadatar kaamon ke liye bahut soft hai aur garam hone par aasaani se khinch jaata hai. Thoda sa carbon, aam taur par ek percent se kam, use steel bana deta hai, jo hard aur strong hai. Chromium aur nickel milao to stainless steel milta hai, mazboot aur rust-proof: steel ki thali ya tiffin box socho.

Steel ek alloy (मिश्रातु) ka example hai: aisa metal jo doosre metals ke saath, ya kisi non-metal ke saath, itna barabar mila ho ki mixture poora ek jaisa ho (homogeneous). Alloys banane ke liye main metal ko pighlaate hain, pighle metal mein doosre elements naap kar ghola jaata hai, aur use thanda hokar jamne diya jaata hai. Mercury wale alloy ka ek khaas naam hai: amalgam.

Definition

Alloy

Ek uniform (homogeneous) mixture jismein metal doosre metals ke saath, ya carbon jaise non-metal ke saath, mila hota hai.

ExampleBrass (copper aur zinc); steel (iron aur carbon).

Alloy banane se properties kaam ke tareekon se badal jaati hain (Table 3.11). Alloy aam taur par apne pure metals se kam temperature par pighalta hai, aur electricity kam achhi tarah conduct karta hai. Isliye ghar ki wiring pure copper ki hoti hai; brass aur bronze taps, statues aur ghantiyon mein jaate hain; aur solder, jo aasaani se pighalta hai, electrical wires jodta hai.

Table 3.11Kuch common alloys

Alloy	Kisse bana	Kyun kaam ka hai	Kis kaam aata hai
Steel	iron + thoda carbon	hard aur strong	buildings, rails, tools
Stainless steel	iron + chromium + nickel	hard; rust nahi hota	bartan, surgical tools
Brass	copper + zinc	sunehra; aasaani se corrode nahi hota	taps, lamps, musical instruments
Bronze	copper + tin	hard; corrosion jhelta hai; achha khanakta hai	statues, ghantiyan, medals
Solder	lead + tin	low melting point	electrical wires jodna
22-carat gold	gold + copper ya silver	pure gold se zyaada hard	jewellery

Practice · 3 questions

Practice: corrosion aur alloys (NCERT in-text questions, p. 55): answers ke saath

Quick answerMediumNCERT in-text Questions p. 55, Q1
Aluminium, iron aur lead ke powders ko alag-alag calcium oxide, iron(III) oxide aur lead(II) oxide ke saath garam kiya jaata hai. Har woh pair chuno jismein metal oxygen le leta hai aur doosre metal ko azaad karta hai.
$A l + C a O$ $A l + F e_{2} O_{3}$ $A l + P b O$ $F e + C a O$ $F e + P b O$ $P b + F e_{2} O_{3}$
Saare sahi options chuno
Solution dikhao
Series Ca > Al > Fe > Pb use karo. Metal sirf apne se neeche wale metal ke oxide ke saath react karta hai: Al $F e_{2} O_{3}$ aur $P b O$ ke saath, aur Fe $P b O$ ke saath. Yahan koi metal calcium se upar nahi hai, isliye CaO kabhi reduce nahi hota.
Short answerEasyNCERT in-text Questions p. 55, Q2
Do metals ke naam batao jo sadiyon tak bina corrode hue chamakte rehte hain, aur batao kyun.
Solution dikhao
AnswerGold aur platinum.
Gold aur platinum itne unreactive hain ki hawa, water aur hawa ke sulphur compounds un par attack nahi karte. (Silver bhi unreactive hai lekin sulphur compounds se dheere-dheere kaala pad jaata hai.)
Short answerEasyNCERT in-text Questions p. 55, Q3
Apne shabdon mein alloy ki definition do. Electrician wires jodne ke liye kaun sa alloy use karega, aur woh kisse bana hai?
Solution dikhao
AnswerMetal ka doosre elements ke saath uniform mixture; solder lead + tin hai.
Alloy aisa metal hai jo doosre metals ke saath, ya carbon jaise non-metal ke saath, uniform tarah se mila ho, taaki uske har hisse ki banawat ek jaisi ho. Solder, jo lead aur tin se bana hai, aasaani se pighalta hai aur electrical wires jodne ke liye use hota hai.

Recap

Summary aur key points

Metals lustrous, malleable, ductile, sonorous aur heat aur electricity ke achhe conductors hote hain; mercury ko chhod kar sab room temperature par solid hain (Section 3.1.1).
Non-metals aam taur par dull, brittle aur poor conductors hote hain, kuch exceptions ke saath: graphite conduct karta hai, iodine lustrous hai, diamond bahut hard hai aur bromine liquid hai (Section 3.1.2).
Metals basic oxides banate hain; non-metals acidic ya neutral oxides banate hain. $A l_{2} O_{3}$ aur $Z n O$ acids aur bases dono ke saath react karte hain: yeh amphoteric hain (Section 3.2.1).
Metals is baat mein alag hain ki woh oxygen, water aur dilute acids ke saath kitni aasaani se react karte hain (Section 3.2.2, Section 3.2.3).
Reactivity series upar potassium se shuru hokar sodium, calcium, magnesium, aluminium, zinc, iron, lead, [hydrogen], copper, mercury aur silver se hote hue neeche gold tak jaati hai (Section 3.2.5).
Hydrogen se upar wale metals use dilute acids se bahar dhakelte hain, aur series mein upar wala metal neeche wale ki jagah uske salt solution mein le leta hai (Section 3.2.4).
Metals electrons kho kar positive ions banate hain aur non-metals electrons le kar negative ions; yeh ions milkar ionic compounds banate hain (Section 3.3).
Non-metals dilute acids se hydrogen ko bahar nahi dhakel sakte, aur hydrogen ke saath judkar hydrides banate hain (Section 3.3).
Ionic compounds high melting points wale hard, brittle solids hain; yeh water mein ghulte hain lekin kerosene mein nahi, aur pighle ya ghule hone par conduct karte hain (Section 3.3.1).
Metals minerals mein free ya compounds ke roop mein milte hain; ore woh mineral hai jisse metal faayde ke saath extract kiya ja sake (Section 3.4).
Metallurgy: ore ko concentrate karo, roasting ya calcination se oxide banao, reactivity ke hisaab se heating, carbon ya electrolysis se reduce karo, phir refine karo (Section 3.4.1).
Electrolytic refining mein metal ke salt ke solution mein impure metal anode aur pure metal cathode hota hai (Section 3.4.6).
Corrosion metal par uske aas-paas ka dheema attack hai; iron ko rust tabhi lagta hai jab hawa aur water dono maujood hon (Section 3.5).
Barriers (paint, oil, grease, chromium ya zinc ki coats) aur alloying rusting ko rokte hain; alloy woh metal hai jo doosre metals ya non-metal ke saath barabar mila ho (Section 3.5.1).

Practice · 20 questions

Practice questions answers ke saath (NCERT “Exercises”)

1
Quick answerEasyNCERT Exercises Q1
Inmein se kaun se pairs displacement reaction denge? Jo bhi sahi hon, saare chuno.
Copper(II) sulphate solution mein zincZinc sulphate solution mein silverMagnesium chloride solution mein ironSilver nitrate solution mein lead
Saare sahi options chuno
Answer dekho
Answer
(A) Copper(II) sulphate solution mein zinc
(D) Silver nitrate solution mein lead
Zinc copper se upar hai aur lead silver se upar hai, isliye yeh do react karte hain. Silver zinc se neeche hai aur iron magnesium se neeche hai, isliye yeh do react nahi karte.
2
Quick answerEasyNCERT Exercises Q2
Har woh tareeka chuno jo monsoon bhar rakhe gaye iron ke tawa ko rust se bachaaye.
Use sukha kar ponchhna aur oil ki patli film laga denaUse geela hi band almaari mein rakh denaUse namak ke paani mein bhige akhbaar mein lapetnaUse silica-gel sachet wale dibbe mein rakhna
Saare sahi options chuno
Answer dekho
Answer
(A) Use sukha kar ponchhna aur oil ki patli film laga dena
(D) Use silica-gel sachet wale dibbe mein rakhna
Oil hawa aur water ko bahar rakhta hai, aur silica gel hawa ko sookha rakhta hai. Geela chhodna ya namkeen kaagaz mein lapetna rusting ko tez karta hai.
Quick answerMediumNCERT Exercises Q3
Ek element X hawa mein jal kar ek white solid deta hai jo sirf 2500 °C se upar pighalta hai. Solid water mein ghulta hai, aur solution red litmus ko blue kar deta hai. X sabse zyaada sambhav hai
sulphurphosphoruscalciumcopper
Answer dekho
Answer (C) calcium
Calcium oxide ionic hai (bahut high melting point) aur water ke saath react karke alkali calcium hydroxide deta hai. Sulphur aur phosphorus acidic oxides dete hain; copper(II) oxide kaala aur insoluble hai.
Quick answerMediumNCERT Exercises Q4
Brass aur copper ke cooking bartanon par khatta khaana pakaane se pehle tin (kalai) ki coat chadhaayi jaati thi. Zinc ki jagah tin kyun?
Zinc patli coating ke liye bahut bhaari haiZinc zyaada reactive hai, isliye khatta khaana us par attack karegaZinc copper par chipak nahi saktaZinc kam reactive hai, isliye woh bartan ko nahi bachaayega
Answer dekho
Answer (B) Zinc zyaada reactive hai, isliye khatta khaana us par attack karega
Series mein zinc tin se upar hai, isliye khatte khaane ke acids zinc coating ke saath react karke zinc salts khaane mein ghol denge. Tin kahin kam reactive aur harmless hai.
5
Short answerMediumNCERT Exercises Q5
Tumhari lab mein sirf ek hammer aur ek LED tester (ek cell, ek LED aur wires) hai.
1. Do tests batao jinse tum anjaan solid elements ko metals aur non-metals mein sort karoge.
  Solution dikhao
  AnswerHammer test aur conduction test.
  Hammer test: sample ko kisi hard surface par peeto. Metal chapta ho jaata hai (malleable) aur khanak sakta hai (sonorous); sulphur ya charcoal jaisa non-metal choora ho jaata hai.
  Conduction test: sample ko tester mein clip karo. Agar LED jalti hai, to sample conduct karta hai, jaise metals karte hain; zyaadatar non-metals nahi karte.
2. Yeh tests kitne bharosemand hain? Har ek ke liye ek element batao jo use bhatka de.
  Solution dikhao
  AnswerGraphite conduction test ko bhatkaata hai; soft alkali metals hammer test ko bhatka sakte hain.
  Dono tests zyaadatar samples ke liye kaam karte hain lekin sabke liye nahi. Graphite ek non-metal hai jo LED jala deta hai. Zinc jaisa metal thanda hone par crack ho sakta hai aur use kai chot chahiye, aur sodium is tarah test karne ke liye bahut soft aur bahut reactive hai. Chemical tests, jaise oxide ka nature, shak wale cases ko tay karte hain.
Short answerMediumNCERT Exercises Q6
Ek white oxide dilute hydrochloric acid mein aur sodium hydroxide solution mein bhi ghulta hai. Yeh kis tarah ka oxide hai? Do oxides suggest karo jo yeh ho sakta hai, aur unmein se ek ke har reaction ki ek equation likho.
Solution dikhao
AnswerAmphoteric, jaise ZnO ya Al₂O₃.
Jo oxide acids aur bases dono ke saath react karke salt aur water de, woh amphoteric hai. Zinc oxide aur aluminium oxide dono white amphoteric oxides hain. Zinc oxide ke liye:
Acid ke saath: $Z n O + 2 H C l$ $\overset{}{\to} Z n C l_{2} + H_{2} O$
Alkali ke saath: $Z n O + 2 N a O H$ $\overset{}{\to} N a_{2} Z n O_{2} + H_{2} O$
Short answerEasyNCERT Exercises Q7
Tumhare paas copper, magnesium, silver aur zinc ki strips aur thoda dilute sulphuric acid hai. Kaun si strips hydrogen dengi? Reactivity series se samjhao.
Solution dikhao
AnswerMagnesium aur zinc denge; copper aur silver nahi denge.
Reactivity series mein magnesium aur zinc hydrogen se upar hain, isliye woh use acid se displace karte hain: hydrogen ke bubbles dikhte hain. Copper aur silver hydrogen se neeche hain, isliye woh use displace nahi kar sakte aur kuch nahi hota.
8
Short answerMediumNCERT Exercises Q8
Ek refinery electrolysis se silver purify karti hai.
1. Anode ke roop mein kya use hota hai?
  Solution dikhao
  AnswerImpure silver ka ek block
  Impure silver ko anode banaya jaata hai, taaki woh ghule.
2. Cathode ke roop mein kya use hota hai?
  Solution dikhao
  AnswerPure silver ki ek patli strip
  Pure silver, pure silver ki patli strip, yaani cathode, par jamta hai.
3. Electrolyte kya hai?
  Solution dikhao
  AnswerSilver salt ka solution, jaise silver nitrate
  Electrolyte mein silver ions hone chahiye, isliye silver nitrate jaise soluble silver salt ka solution use hota hai.
4. Impure silver mein jo bhi gold hai, woh kahan jaayega?
  Solution dikhao
  AnswerAnode mud mein
  Gold silver se kam reactive hai aur ghulta nahi, isliye woh anode ke neeche anode mud ban kar gir jaata hai.
9
Short answerMediumNCERT Exercises Q9
Ananya ek gas jar ke andar deflagrating spoon mein thoda sulphur jalaati hai, phir jar mein litmus ki strips utaarti hai.
1. Sookhe blue litmus paper ki strip ka kya hota hai?
  Solution dikhao
  AnswerKoi badlaav nahi
  Sookhi sulphur dioxide khud acid nahi hai, isliye sookha litmus nahi badalta.
2. Geele blue litmus paper ki strip ka kya hota hai?
  Solution dikhao
  AnswerWoh red ho jaati hai
  Geele paper par gas ghul kar sulphurous acid banati hai, jo blue litmus ko red kar deta hai.
3. Jalne aur gas ke water mein ghulne ki balanced equations likho.
  Solution dikhao
  Jalna: $S + O_{2} \overset{}{\to} S O_{2}$ .
  Ghulna: $S O_{2} + H_{2} O$ $\overset{}{\to} H_{2} S O_{3}$ .
10
Short answerEasyNCERT Exercises Q10
Har cheez ke liye rusting rokne ka sahi tareeka suggest karo.
1. Cycle ki chain
  Solution dikhao
  AnswerOil ya grease lagaana
  Oil ya grease hawa aur water ko bahar rakhte hain aur links ko aasaani se chalne bhi dete hain; paint toot kar utar jaata.
2. Corrugated iron ki chhat
  Solution dikhao
  AnswerGalvanising
  Zinc coating scratch lagne par bhi bachaati hai.
3. Car ki body
  Solution dikhao
  AnswerPaint karna (primer ke upar)
  Paint barrier banata hai aur achha finish deta hai; bahut si car bodies neeche se galvanised bhi hoti hain.
Quick answerEasyNCERT Exercises Q11
Carbon dioxide water mein ghul kar aisa solution deta hai jiska pH 7 se kam hai. Isse pata chalta hai ki non-metals ke oxides aam taur par hote hain
basicacidic (kuch neutral hote hain)amphotericalkaline
Answer dekho
Answer (B) acidic (kuch neutral hote hain)
$C O_{2}$ aur $S O_{2}$ jaise non-metal oxides acidic hain. Kuch, jaise carbon monoxide, neutral hain.
12
Short answerMediumNCERT Exercises Q12
Kaaran batao.
1. Puraane zamaane ke silver aur gold ke coins aaj bhi achhi haalat mein milte hain.
  Solution dikhao
  Silver aur gold reactivity series ke neeche ke paas hain, isliye hawa aur water un par mushkil se attack karte hain. Woh sadiyon tak apni shape aur lustre banaaye rakhte hain.
2. Teacher potassium ko paraffin oil mein rakhte hain, kabhi water mein nahi.
  Solution dikhao
  Potassium water ke saath violently aur hawa ke saath tezi se react karta hai, aur bani hui hydrogen aag pakad sakti hai. Paraffin oil iske saath react nahi karta aur hawa aur nami dono ko door rakhta hai.
3. Aluminium reactivity series mein upar hai, phir bhi pressure-cooker ki body isi se banti hai.
  Solution dikhao
  Surface par aluminium oxide ki ek patli, mazboot layer ban jaati hai jo aage ka reaction rok deti hai. Aluminium halka bhi hai aur heat ka achha conductor bhi.
4. Lead extract karne se pehle galena (PbS) ko lead(II) oxide mein badla jaata hai.
  Solution dikhao
  Metal oxide ko (carbon se) reduce karna sulphide se kahin aasaan hai, isliye sulphide ore ko pehle roast karke oxide banaya jaata hai.
Short answerMediumNCERT Exercises Q13
Brass ke diyas Diwali ke kuch hafte baad dull aur hare-se ho jaate hain. Unhe nimbu ke ras (ya imli) aur namak ke paste se ragadne par woh phir kyun chamakne lagte hain?
Solution dikhao
AnswerAcid basic copper carbonate (ya oxide) ki coat ko ghol deta hai.
Dull hari ya gehri coating basic copper carbonate (aur copper oxide) hai, jo brass ke copper ke nami wali hawa ke saath react karne se bani hai. Yeh compounds basic hain.
Nimbu ke ras mein citric acid aur imli mein tartaric acid hota hai. Acid basic coating ke saath react karke use salts mein badal deta hai jo paani se dhul jaate hain, aur neeche ka fresh chamakdaar metal saamne aa jaata hai.

Long answerMediumNCERT Exercises Q14

Ek metal aur ek non-metal ko teen chemical points par compare karo: bana hua oxide, bana hua ion, aur dilute acids ke saath reaction. Sodium aur sulphur ko examples ki tarah use karo, aur non-metal se banne wale ek hydride ka naam batao.

Solution dikhao

AnswerBasic vs acidic oxide; positive vs negative ion; hydrogen displace karta hai vs nahi karta.

Table 3.12

Point	Sodium (metal)	Sulphur (non-metal)
Oxide	$N a_{2} O$ , basic; NaOH deta hai	$S O_{2}$ , acidic; $H_{2} S O_{3}$ deta hai
Ion	1 electron khota hai: $N a^{+}$	2 electrons leta hai: $S^{2 -}$
Dilute acids	hydrogen displace karta hai (violently)	hydrogen nahi

Non-metals hydrogen ke saath judkar hydrides banate hain, jaise hydrogen sulphide, $H_{2} S$ .

15
Short answerHardNCERT Exercises Q15
Sadak kinaare ka ek polish wala dull gold earrings ki jodi ko 'naye jaisa' chamkaane ki offer deta hai. Woh unhe ek minute ke liye dhuaan chhodte peele-se liquid mein dubaata hai, dhota hai aur chamakte hue wapas de deta hai. Ghar par earrings ka wazan 10.0 g ki jagah 9.2 g nikalta hai.
1. Usne shaayad kaun sa liquid use kiya?
  Solution dikhao
  AnswerAqua regia
  Aqua regia, jo concentrated $H C l$ ke teen hisson aur concentrated $H N O_{3}$ ke ek hisse se taaza banaya jaata hai, un gine-chune liquids mein se hai jo gold ko ghol dete hain.
2. Earrings ke mass ka kitna percentage kam hua?
  %
  Solution dikhao
  Kami $= 10.0 - 9.2 = 0.8 g$ , isliye kam hua percentage $0.8 / 10.0 \times 100 = 8 %$ hai. Woh gold uske liquid mein reh gaya.
3. Liquid ke dono acids mein se koi bhi akele aisa kyun nahi karta?
  Solution dikhao
  AnswerSirf mixture gold ko ghol sakta hai.
  Gold itna unreactive hai ki koi bhi concentrated acid akele us par attack nahi karta; sirf mixture, aqua regia, use ghol sakta hai. Phir neeche ki fresh gold surface chamakti hai.
Short answerMediumNCERT Exercises Q16
Solar water heaters aur geysers mein aksar saade steel ki jagah copper tanks, ya copper ki lining wale tanks, use hote hain. Do kaaran batao.
Solution dikhao
AnswerCopper garam water ke saath react nahi karta; yeh heat achhi tarah conduct karta hai.
Reactivity series mein copper hydrogen se neeche hai aur water ke saath, garam water ke saath bhi, react nahi karta. Steel, jo zyaadatar iron hai, ghuli hawa wale garam water mein rust ho jaata.
Copper heat ka bahut achha conductor bhi hai, isliye water jaldi garam hota hai.
Quick answerMedium
Assertion (A): Aluminium ke bartan aasaani se corrode nahi hote, haalaanki aluminium ek reactive metal hai. Reason (R): Surface par aluminium oxide ki patli layer neeche ke metal ko bachaati hai.
A aur R dono sahi hain, aur R, A ko samjhaata haiA aur R dono sahi hain, lekin R, A ko nahi samjhaataA sahi hai, lekin R galat haiA galat hai, lekin R sahi hai
Answer dekho
Answer (A) A aur R dono sahi hain, aur R, A ko samjhaata hai
Dono statements sahi hain, aur protective oxide layer hi wajah hai ki aluminium corrosion jhel leta hai.
Quick answerMedium
Assertion (A): Copper dilute hydrochloric acid ke saath hydrogen nahi deta. Reason (R): Reactivity series mein copper hydrogen se upar hai.
A aur R dono sahi hain, aur R, A ko samjhaata haiA aur R dono sahi hain, lekin R, A ko nahi samjhaataA sahi hai, lekin R galat haiA galat hai, lekin R sahi hai
Answer dekho
Answer (C) A sahi hai, lekin R galat hai
A sahi hai, lekin copper hydrogen se neeche hai, isliye R galat hai. Hydrogen se neeche hona hi wajah hai ki copper hydrogen nahi deta.
Quick answerEasy
Carbonate ore ko kam ya bilkul nahi hawa mein garam karna kehlaata hai, aur sulphide ore ko bahut saari hawa mein garam karna kehlaata hai.
Answer dekho
Answer (1) calcination, (2) roasting
Calcination carbonates ke liye seemit hawa mein hota hai; roasting sulphides ke liye zyaada hawa mein.
Quick answerMedium
Aluminium atom ka atomic number 13 hai. Ion banaate waqt yeh kitne electrons khota hai?
electrons
Answer dekho
Answer 3 electrons
Aluminium 2, 8, 3 hai. Teen outer electrons khone par 2, 8 bachta hai, ek poora octet, isliye yeh $A l^{3 +}$ banata hai.

Apna NCERT exercise question dhoondo

Hamare practice questions ncert.ai ke liye likhe gaye hain aur NCERT exercises ko follow karte hain. Apni textbook ke question se match karne wala question dhoondo; uska answer uske saath hai.

Tumhari NCERT textbook mein	Yahan practice question
NCERT in-text Questions p. 40, Q1	Practice: physical properties (NCERT in-text questions, p. 40) · Q1
NCERT in-text Questions p. 40, Q2	Practice: physical properties (NCERT in-text questions, p. 40) · Q2
NCERT in-text Questions p. 46, Q1	Practice: reactivity (NCERT in-text questions, p. 46) · Q1
NCERT in-text Questions p. 46, Q2	Practice: reactivity (NCERT in-text questions, p. 46) · Q2
NCERT in-text Questions p. 46, Q3	Practice: reactivity (NCERT in-text questions, p. 46) · Q3
NCERT in-text Questions p. 46, Q4	Practice: reactivity (NCERT in-text questions, p. 46) · Q4
NCERT in-text Questions p. 46, Q5	Practice: reactivity (NCERT in-text questions, p. 46) · Q5
NCERT in-text Questions p. 49, Q1	Practice: ionic compounds (NCERT in-text questions, p. 49) · Q1
NCERT in-text Questions p. 49, Q2	Practice: ionic compounds (NCERT in-text questions, p. 49) · Q2
NCERT in-text Questions p. 53, Q1	Practice: occurrence aur extraction (NCERT in-text questions, p. 53) · Q1
NCERT in-text Questions p. 53, Q2	Practice: occurrence aur extraction (NCERT in-text questions, p. 53) · Q2
NCERT in-text Questions p. 53, Q3	Practice: occurrence aur extraction (NCERT in-text questions, p. 53) · Q3
NCERT in-text Questions p. 55, Q1	Practice: corrosion aur alloys (NCERT in-text questions, p. 55) · Q1
NCERT in-text Questions p. 55, Q2	Practice: corrosion aur alloys (NCERT in-text questions, p. 55) · Q2
NCERT in-text Questions p. 55, Q3	Practice: corrosion aur alloys (NCERT in-text questions, p. 55) · Q3
NCERT Exercises Q1	Exercises · Q1
NCERT Exercises Q2	Exercises · Q2
NCERT Exercises Q3	Exercises · Q3
NCERT Exercises Q4	Exercises · Q4
NCERT Exercises Q5	Exercises · Q5
NCERT Exercises Q6	Exercises · Q6
NCERT Exercises Q7	Exercises · Q7
NCERT Exercises Q8	Exercises · Q8
NCERT Exercises Q9	Exercises · Q9
NCERT Exercises Q10	Exercises · Q10
NCERT Exercises Q11	Exercises · Q11
NCERT Exercises Q12	Exercises · Q12
NCERT Exercises Q13	Exercises · Q13
NCERT Exercises Q14	Exercises · Q14
NCERT Exercises Q15	Exercises · Q15
NCERT Exercises Q16	Exercises · Q16

Quick check: MCQs

3.1.2 Non-metals4 questions
3.2.2 Metals Water ke saath react karein to kya hota hai?4 questions
3.2.5 Reactivity Series4 questions
3.3.1 Ionic Compounds ki Properties4 questions
3.4.6 Metals ki Refining4 questions
3.5.1 Corrosion se Bachaav4 questions

Glossary · 15

Key terms (English + Hindi)

alloyमिश्रातुmishraatu: Doosre metals ya kisi non-metal ke saath barabar mila hua metal, jaise brass ya steel.Chapter mein pehli baar yahan aaya →
amphoteric oxideउभयधर्मी ऑक्साइडubhaydharmi oxide: Aisa metal oxide, jaise $A l_{2} O_{3}$ ya $Z n O$ , jo acids aur bases dono ke saath react karke salt aur water deta hai.Chapter mein pehli baar yahan aaya →

calcinationनिस्तापनnistaapan: Carbonate ore ko kam ya bilkul nahi hawa mein tez garam karke oxide mein badalna.Chapter mein pehli baar yahan aaya →
corrosionसंक्षारणsankshaaran: Aas-paas ki hawa, nami ya chemicals se metal ka dheere-dheere ghisna; iron ka rust hona iska example hai.Chapter mein pehli baar yahan aaya →

ductileतन्यtanya: Jise kheench kar patli wire banaya ja sake; gold ko kisi bhi doosre metal se zyaada patla kheencha ja sakta hai.Chapter mein pehli baar yahan aaya →

electrolytic refiningविद्युत-अपघटनी परिष्करणvidyut-apghatani parishkaran: Electrolysis se metal ko purify karna, jismein impure metal anode aur pure metal cathode hota hai.Chapter mein pehli baar yahan aaya →

galvanisationयशदलेपनyashadlepan: Iron ya steel ko rust se bachaane ke liye us par zinc ki patli coat chadhaana.Chapter mein pehli baar yahan aaya →
gangueगैंगgaing: Ore ke saath mili mitti, ret aur patthar, jo metal extract karne se pehle hataaye jaate hain.Chapter mein pehli baar yahan aaya →

ionic compoundआयनिक यौगिकaayanik yaugik: Positive aur negative ions ka compound jo electrostatic attraction se juda rehta hai, aur metal se non-metal ko electron transfer se banta hai.Chapter mein pehli baar yahan aaya →

malleableआघातवर्ध्यaaghaatvardhya: Jise bina toote peet kar ya roll karke patli sheets banaya ja sake, jaise gold, silver aur aluminium.Chapter mein pehli baar yahan aaya →
metallurgyधातुकर्मdhaatukarm: Metals ko unke ores se nikaalna aur use ke liye purify karna.Chapter mein pehli baar yahan aaya →
mineralखनिजkhanij: Earth ke crust mein milne wala natural roop se bana element ya compound.Chapter mein pehli baar yahan aaya →

oreअयस्कayask: Aisa mineral jisse metal faayde ke saath extract kiya ja sake.Chapter mein pehli baar yahan aaya →

reactivity seriesसक्रियता श्रेणीsakriyata shreni: Metals ki list, sabse reactive (potassium) se sabse kam reactive (gold) tak, jismein comparison ke liye hydrogen bhi rakha gaya hai.Chapter mein pehli baar yahan aaya →
roastingभर्जनbharjan: Sulphide ore ko bahut saari hawa mein tez garam karke oxide mein badalna.Chapter mein pehli baar yahan aaya →

3.1 Physical Properties

3.1.1 Metals

3.1.2 Non-metals

3.2 Metals ki Chemical Properties

3.2.1 Metals ko Hawa mein jalaane par kya hota hai?

3.2.2 Metals Water ke saath react karein to kya hota hai?

3.2.3 Metals Acids ke saath react karein to kya hota hai?

3.2.4 Metals doosre Metal Salts ke Solutions ke saath kaise react karte hain?

3.2.5 Reactivity Series

3.3 Metals aur Non-metals kaise React karte hain?

3.3.1 Ionic Compounds ki Properties

3.4 Metals kahan milte hain

3.4.1 Metals ka Extraction

3.4.2 Ores ka Enrichment

3.4.3 Activity Series mein Neeche wale Metals ko Extract karna

3.4.4 Activity Series ke Beech wale Metals ko Extract karna

3.4.5 Activity Series mein Upar wale Metals ko Extract karna

3.4.6 Metals ki Refining

3.5 Corrosion

3.5.1 Corrosion se Bachaav

Apna NCERT exercise question dhoondo

Quick check: MCQs

Tum chapter ke end tak pahunch gaye