Class 10 Science · Chapter 3
Short answer: NCERT Class 10 Science Chapter 3 Metals and Non-metals me 16 in-text aur 16 exercise questions hain. Chapter me physical/chemical properties, reactivity series, ionic bonding, metallurgy (extraction ke teen steps), corrosion aur alloys padhaye jaate hain. Har question ka step-by-step solution neeche diya gaya hai.
Chapter 3 Chemistry ka sabse content-heavy chapter hai. Reactivity series aur metallurgy ke steps yaad ho gaye to aadha chapter khatam. Ye Chapter 1 ke displacement reactions ka seedha extension hai.
Chapter 3 Summary — 5 Minute Revision
Physical properties
| Property | Metals | Non-metals |
|---|---|---|
| Lustre | Chamakdaar | Chamak nahi (iodine exception) |
| Malleable / Ductile | Haan | Nahi — bhurbhure (brittle) |
| Conductivity | Achhe conductor | Kharab (graphite exception) |
| State | Solid (mercury liquid) | Solid, liquid (bromine), gas |
| Sonorous | Haan | Nahi |
↔ Table ko side me swipe karein
Reactivity series (upar se neeche — reactivity ghat ti hai)
K > Na > Ca > Mg > Al > Zn > Fe > Pb > [H] > Cu > Hg > Ag > Au
Yaad karne ka tarika: "Kal Nani Cafe Mage Aloo Zinda Fel Pb — Hydrogen — Cuch Hg Agar Aur." Hydrogen se upar wale metals hi dilute acid se H2 nikal sakte hain.
Ionic (electrovalent) compounds
- Metal electron deta hai (cation), non-metal electron leta hai (anion).
- High melting/boiling point — strong electrostatic force todne me zyada energy lagti hai.
- Paani me ghulnshil, kerosene/petrol me nahi.
- Solid me current nahi, par pighli hui ya solution me conduct karte hain (ions free ho jaate hain).
Metallurgy — 3 steps
- Concentration — ore se gangue hataana
- Oxide me badalna — carbonate ka calcination (hawa ke bina garam), sulphide ka roasting (hawa me garam)
- Reduction — oxide se metal nikalna (carbon se, ya bahut reactive metals ke liye electrolysis se)
Ant me electrolytic refining se shuddh metal milta hai.
Corrosion se bachav
Painting, oiling/greasing, galvanisation (zinc ki parat), anodising, alloying (jaise stainless steel).
In-Text Questions — Solutions
Q1. Aise metal ke udaharan dijiye jo — liquid ho / knife se kate / best conductor / poor conductor
- (i) Room temperature par liquid: Mercury (Hg)
- (ii) Knife se aasani se kat jaye: Sodium (Na), Potassium (K)
- (iii) Heat ka sabse achha conductor: Silver (Ag)
- (iv) Heat ka kharab conductor: Lead (Pb), Mercury (Hg)
Q2. Malleable aur Ductile ka matlab
Malleable — wo property jiski wajah se metal ko peet kar patli chaadar (sheet) banayi ja sakti hai. Jaise aluminium foil, silver foil.
Ductile — wo property jiski wajah se metal ko kheench kar patla taar (wire) banaya ja sakta hai. Gold sabse zyada ductile hai.
Q3. Sodium ko kerosene me duba kar kyun rakhte hain?
Sodium bahut zyada reactive hai. Hawa ke sampark me aate hi wo khud jal uthta hai aur namee ke saath tez reaction karta hai:
2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g) + Heat
Kerosene sodium ko hawa ki oxygen aur namee se alag rakhta hai, isliye ise kerosene me dubo kar rakha jata hai — ye ek safety measure hai.
Q4. Iron + steam, aur calcium/potassium + water ke equations
(i) Iron + steam:
3Fe(s) + 4H2O(g) → Fe3O4(s) + 4H2(g)
(ii) Calcium + water — reaction kam tez, nikli hui gas ke bubbles calcium se chipak jaate hain isliye wo tairne lagta hai:
Ca(s) + 2H2O(l) → Ca(OH)2(aq) + H2(g)
Potassium + water — itni heat nikalti hai ki hydrogen turant aag pakad leta hai:
2K(s) + 2H2O(l) → 2KOH(aq) + H2(g) + Heat
Q5. Chaar metals A, B, C, D — sabse reactive kaun? Reactivity ka kram?
Table ke anusaar B iron(II) sulphate se bhi iron ko displace kar deta hai, jabki A sirf copper ko displace karta hai, C sirf silver ko, aur D kisi ko nahi.
(i) Sabse reactive metal: B
(ii) B ko copper(II) sulphate me daalne par: B copper ko displace kar dega. Solution ka neela rang halka pad kar khatam ho jayega aur bartan me laal-bhoora copper jam jayega.
(iii) Ghatte hue reactivity ka kram: B > A > C > D
Q6. Reactive metal + dilute HCl se kaunsi gas? Iron + dilute H2SO4 ka equation
Hydrogen gas (H2) nikalti hai.
Fe(s) + H2SO4(aq) → FeSO4(aq) + H2(g)
Q7. Iron(II) sulphate me zinc daalne par kya hoga?
Zinc, iron se zyada reactive hai, isliye wo iron ko displace kar dega — displacement reaction:
Zn(s) + FeSO4(aq) → ZnSO4(aq) + Fe(s)
Observation: FeSO4 ka halka hara rang khatam hokar solution colourless ho jayega, aur zinc par bhoora-kala iron jam jayega.
Q8. Sodium, oxygen aur magnesium ki electron-dot structure aur Na2O / MgO ka banna
(i) Electron-dot structures:
- Sodium (Na), 2,8,1 — bahari shell me 1 electron
- Oxygen (O), 2,6 — bahari shell me 6 electrons
- Magnesium (Mg), 2,8,2 — bahari shell me 2 electrons
(ii) Electron transfer se banna:
Na2O — do sodium atoms ek-ek electron dete hain, oxygen dono le leta hai:
2Na → 2Na+ + 2e− ; O + 2e− → O2− ⟹ Na2O
MgO — magnesium do electron deta hai, oxygen dono le leta hai:
Mg → Mg2+ + 2e− ; O + 2e− → O2− ⟹ MgO
(iii) Ions: Na2O me Na+ aur O2−; MgO me Mg2+ aur O2−.
Q9. Ionic compounds ka melting point zyada kyun hota hai?
Ionic compounds me viprit aavesh wale ions ke beech bahut majboot electrostatic force of attraction hota hai. In bandhno ko todne ke liye kaafi zyada energy chahiye hoti hai — isliye inka melting aur boiling point bahut ooncha hota hai.
Q10. Mineral, Ore aur Gangue ki paribhasha
(i) Mineral — prithvi me prakritik roop se paye jaane wale wo yaugik/tatv jinme metals hote hain.
(ii) Ore — wo minerals jinse metal ko laabhkari (profitable) tarike se nikala ja sake. Har ore mineral hota hai, par har mineral ore nahi hota.
(iii) Gangue — ore ke saath nikli hui mitti, ret aur dusri anchahi impurities.
Q11. Do metals jo prakriti me free state me milte hain
Gold (Au) aur Platinum (Pt). Silver aur copper bhi kabhi-kabhi free state me milte hain. Ye reactivity series me sabse neeche hain, isliye hawa/paani se react nahi karte aur shuddh roop me mil jaate hain.
Q12. Metal oxide se metal nikalne ke liye kaunsi rasayanik prakriya use hoti hai?
Reduction. Oxide ko carbon (coke) ya kisi zyada reactive metal ke saath garam karke metal nikala jata hai:
ZnO(s) + C(s) → Zn(s) + CO(g)
3MnO2(s) + 4Al(s) → 3Mn(l) + 2Al2O3(s) + Heat
Bahut reactive metals (Na, K, Ca, Mg, Al) ke liye reduction electrolysis se ki jaati hai.
Q13. Zinc, magnesium aur copper ke oxides ko metals ke saath garam karne par displacement kab hoga?
Displacement tabhi hoga jab milaya gaya metal, oxide wale metal se zyada reactive ho. Reactivity: Mg > Zn > Cu.
| Reaction | Hoga? |
|---|---|
| ZnO + Mg → MgO + Zn | ✅ Haan |
| CuO + Zn → ZnO + Cu | ✅ Haan |
| CuO + Mg → MgO + Cu | ✅ Haan |
| ZnO + Cu | ❌ Nahi |
| MgO + Zn | ❌ Nahi |
| MgO + Cu | ❌ Nahi |
↔ Table ko side me swipe karein
Q14. Kaunse metals aasani se corrode nahi hote?
Gold (Au), Platinum (Pt) aur kaafi had tak Silver (Ag). Ye reactivity series me sabse neeche hain, isliye hawa ki oxygen aur namee se aasani se react nahi karte.
Q15. Alloys kya hote hain?
Alloy do ya do se zyada metals ka (ya ek metal aur ek non-metal ka) samangi mishran (homogeneous mixture) hota hai.
Alloy banane se metal ki properties behtar ho jaati hain — zyada mazbooti, kam corrosion, behtar look.
- Steel = Iron + Carbon
- Stainless steel = Iron + Nickel + Chromium
- Brass = Copper + Zinc
- Bronze = Copper + Tin
- Solder = Lead + Tin (kam melting point — taar jodne me)
- Amalgam = koi metal + Mercury
Q16. Metals aur non-metals ke oxides ki prakriti me antar
Metal oxides basic hote hain — paani me ghulkar base bante hain aur acid se react karte hain.
Na2O + H2O → 2NaOH
Non-metal oxides acidic hote hain — paani me ghulkar acid bante hain.
SO2 + H2O → H2SO3
Amphoteric oxides (Al2O3, ZnO) acid aur base dono se react karte hain.
Poore Class 10 Science ke handwritten colour notes
IITian & district toppers ke banaye short notes — revision-ready, diagram ke saath. Board se pehle poora syllabus 3 din me revise.
Exercise Questions — Solutions (Q1–Q16)
Q1. Kaunsa jodaa displacement reaction dega?
Answer: (d) AgNO3 solution aur copper metal
Copper, silver se zyada reactive hai, isliye wo silver ko displace kar dega:
Cu(s) + 2AgNO3(aq) → Cu(NO3)2(aq) + 2Ag(s)
Baki options me milaya gaya metal kam reactive hai, isliye reaction nahi hoga.
Q2. Iron ki frying pan ko rusting se bachane ka sabse achha tarika?
Answer: (c) Zinc ki coating chadhana (galvanisation)
Frying pan garam hoti hai aur baar-baar dhoyi jaati hai, isliye grease ya paint tikta nahi. Zinc ki parat iron se zyada reactive hai — wo khud corrode hokar iron ko bachati hai, aur garmi me bhi bani rehti hai.
Q3. Oxygen se high melting point wala paani me ghulnshil compound banane wala element?
Answer: (a) Calcium
Calcium ek metal hai — uska oxide (CaO) ionic hai, isliye melting point bahut ooncha hai aur wo paani me ghulkar Ca(OH)2 banata hai. Carbon aur silicon non-metals hain (acidic/covalent oxides), aur iron oxide paani me ghulnshil nahi hai.
Q4. Food cans par zinc ke bajaye tin ki coating kyun hoti hai?
Answer: (c) Zinc, tin se zyada reactive hai
Zinc khane me maujood acids ke saath react karke zehreele compounds bana sakta hai. Tin kam reactive hai, isliye khana surakshit rehta hai.
Q5. Hammer, battery, bulb, wire aur switch se metal-non-metal kaise pehchaanenge?
(a) Do test:
- Hammer test (malleability): sample par hathoda maariye. Metal peet kar chapta ho jayega; non-metal tukdon me toot jayega (brittle).
- Conductivity test: battery, bulb, switch aur sample se circuit banaiye. Bulb jale to metal, na jale to non-metal.
(b) Upyogita: ye test aam taur par bahut upyogi hain, par puri tarah bharosemand nahi. Kuch apwaad hain — graphite non-metal hokar bhi bijli conduct karta hai, aur sodium metal hokar bhi bahut mulayam hai. Isliye nishkarsh ke liye dono test saath me karne chahiye.
Q6. Amphoteric oxides kya hain? Do udaharan
Wo metal oxides jo acid aur base dono ke saath react karke salt aur paani banate hain, unhe amphoteric oxides kehte hain.
Udaharan: Aluminium oxide (Al2O3) aur Zinc oxide (ZnO).
Al2O3 + 6HCl → 2AlCl3 + 3H2O
Al2O3 + 2NaOH → 2NaAlO2 + H2O
Q7. Do metals jo dilute acid se hydrogen displace karein, aur do jo na karein
Hydrogen displace karne wale (reactivity series me hydrogen se upar): Zinc (Zn) aur Magnesium (Mg). Iron aur aluminium bhi karte hain.
Zn + 2HCl → ZnCl2 + H2↑
Na karne wale (hydrogen se neeche): Copper (Cu) aur Silver (Ag). Gold aur platinum bhi nahi karte.
Q8. Electrolytic refining me anode, cathode aur electrolyte kya lenge?
Kisi metal M ke electrolytic refining me:
- Anode — ashuddh (impure) metal M ki moti plate
- Cathode — shuddh metal M ki patli strip
- Electrolyte — metal M ke salt ka solution (jaise copper ke liye acidified CuSO4)
Current chalane par anode se shuddh metal ghul kar cathode par jam jata hai, aur impurities (anode mud) anode ke neeche baith jaati hain.
Q9. Sulphur ko jalane se nikli gas ka litmus par kya asar? Equation likhiye
Sulphur jalne par sulphur dioxide (SO2) gas nikalti hai — ye ek acidic oxide hai.
(a)(i) Sookhe litmus paper par: koi asar nahi — paani ke bina gas ionise nahi hoti, H+ nahi bante.
(a)(ii) Geele litmus paper par: neela litmus laal ho jayega, kyunki SO2 paani se milkar sulphurous acid banata hai.
(b) Equations:
S(s) + O2(g) → SO2(g)
SO2(g) + H2O(l) → H2SO3(aq)
Q10. Iron ki rusting rokne ke do tarike
- Painting / oiling / greasing — iron ki surface par parat chadha kar use hawa ki oxygen aur namee se alag kar dena.
- Galvanisation — iron par zinc ki parat chadhana. Zinc iron se zyada reactive hai, isliye wo khud corrode hoker iron ko bachata hai (sacrificial protection).
Alloying (jaise stainless steel banana) bhi ek sthayi upay hai.
Q11. Non-metals oxygen se milkar kis prakar ke oxides banate hain?
Acidic oxides. Ye paani me ghulkar acid banate hain aur base ke saath react karte hain.
CO2 + H2O → H2CO3
SO3 + H2O → H2SO4
Kuch non-metal oxides neutral bhi hote hain — jaise CO, N2O aur H2O.
Q12. Kaaran bataiye (a) se (d)
(a) Platinum, gold aur silver se jewellery kyun? Ye bahut kam reactive hain — hawa, namee aur acid se corrode nahi hote, isliye inki chamak saalon tak bani rehti hai. Saath hi ye bahut malleable aur ductile hain.
(b) Sodium, potassium aur lithium tel me kyun? Ye itne reactive hain ki hawa ke sampark me aate hi jal uthte hain aur paani se tez reaction karte hain. Tel inhe hawa aur namee se alag rakhta hai.
(c) Aluminium reactive hai phir bhi bartan kyun? Hawa me aate hi aluminium par aluminium oxide ki patli, majboot parat ban jaati hai jo andar ke metal ko aage corrode hone se rokti hai. Saath hi wo halka hai aur heat ka achha conductor hai.
(d) Carbonate aur sulphide ores ko oxide me kyun badalte hain? Kyunki oxide ko reduce karna sabse aasan hai — carbonate ya sulphide se seedha metal nikalna mushkil hai. Isliye carbonate ka calcination aur sulphide ka roasting karke pehle oxide banaya jata hai.
Q13. Copper ke bartan nimbu ya imli se kyun saaf hote hain?
Copper hawa ki namee aur CO2 se milkar basic copper carbonate ki hari parat bana leta hai — isse bartan dhundhla (tarnished) dikhta hai.
Nimbu aur imli me citric aur tartaric acid hote hain. Ye acid us basic hari parat ko neutralise karke ghol dete hain, jisse bartan dobara chamak jata hai.
Q14. Rasayanik gundhon ke aadhar par metal aur non-metal me antar
| Metals | Non-metals |
|---|---|
| Electron khote hain — cation banate hain | Electron lete hain — anion banate hain |
| Oxides basic (kuch amphoteric) | Oxides acidic (kuch neutral) |
| Dilute acid se H2 nikalte hain | Dilute acid se H2 nahi nikalte |
| Reducing agent hain | Aam taur par oxidising agent hain |
| Hydrogen ke saath aam taur par react nahi karte | Hydrogen ke saath covalent hydrides banate hain |
↔ Table ko side me swipe karein
Q15. Nakli sunar ne kaunsa solution use kiya jisse bangles ka wazan ghat gaya?
Us aadmi ne aqua regia use kiya tha.
Aqua regia = 3 bhaag concentrated HCl + 1 bhaag concentrated HNO3. Ye duniya ka ek matra aam mishran hai jo gold ko ghol sakta hai.
Bangles ki upar ki parat ghul gayi — isliye wo naye jaise chamakne lage, par unka wazan kaafi ghat gaya. Ghula hua gold aadmi ke paas reh gaya.
Q16. Garam paani ki tank copper se banti hai, steel se kyun nahi?
Copper garam paani (aur steam) ke saath react nahi karta, jabki iron/steel garam paani aur steam ke saath react karke iron oxide bana leta hai — tank jang khakar leak karne lagegi.
3Fe(s) + 4H2O(g) → Fe3O4(s) + 4H2(g)
Saath hi copper heat ka bahut achha conductor hai, isliye paani jaldi garam hota hai.
Important Equations — Ek Nazar Me
| Concept | Equation / Rule | Yaad rakhein |
|---|---|---|
| Reactivity series | K > Na > Ca > Mg > Al > Zn > Fe > Pb > H > Cu > Hg > Ag > Au | H se upar wale hi acid se H2 dete hain |
| Metal + Water | 2Na + 2H2O → 2NaOH + H2 | Sirf reactive metals |
| Iron + Steam | 3Fe + 4H2O → Fe3O4 + 4H2 | Fe3O4, Fe2O3 nahi |
| Metal + Acid | Zn + 2HCl → ZnCl2 + H2 | Pop test |
| Amphoteric oxide | Al2O3 + 6HCl / + 2NaOH | Al2O3, ZnO |
| Calcination | ZnCO3 Δ→ ZnO + CO2 | Carbonate, hawa ke bina |
| Roasting | 2ZnS + 3O2 → 2ZnO + 2SO2 | Sulphide, hawa me |
| Reduction (carbon) | ZnO + C → Zn + CO | Madhyam reactive metals |
| Thermite | Fe2O3 + 2Al → 2Fe + Al2O3 | Railway track welding |
| Aqua regia | 3 HCl (conc.) : 1 HNO3 (conc.) | Gold ghol deta hai |
↔ Table ko side me swipe karein
Common Mistakes — Yahan Marks Kat te Hain
- Iron + steam ka product galat likhna. Sahi hai Fe3O4, Fe2O3 nahi. Har saal galat hota hai.
- Calcination aur roasting mila dena. Calcination = carbonate, hawa ke bina. Roasting = sulphide, hawa me. Do alag-alag cheezein hain.
- Electrolytic refining me anode-cathode ulta likhna. Anode = impure metal, cathode = pure metal.
- Aqua regia ka ratio ulta likhna. Sahi: 3 HCl : 1 HNO3, ulta nahi.
- Amphoteric oxide ka sirf ek reaction likhna. Marks tabhi milenge jab acid aur base dono ke saath equation likhi ho.
- Q5(b) me sirf "haan upyogi hai" likh dena. Apwaad (graphite conduct karta hai, sodium mulayam hai) likhna zaroori hai — wahi asli marks hain.
Board-Style Important Questions
- 1 mark: Aqua regia kya hai? Iska ek upyog likhiye.
- 2 marks: Calcination aur roasting me antar spasht kijiye, ek-ek equation ke saath.
- 3 marks: Amphoteric oxide kya hai? Al2O3 ke acid aur base ke saath equations likhiye.
- 3 marks: Galvanisation kya hai? Ye iron ko rust se kaise bachata hai? Ek aur tarika likhiye.
- 5 marks: Ek ore se metal nikalne ke teen charan samjhaiye aur har charan ki ek equation likhiye. Bahut reactive metals ke liye alag tarika kyun chahiye?
Quick Quiz — Score Check Karein
Q1. Reactivity series me sabse zyada reactive metal kaunsa hai?
Q2. Sodium metal ko kerosene me kyun dubo kar rakha jata hai?
Q3. Iron(II) sulphate (FeSO4) solution me zinc metal daalne par kya hota hai?
Q4. Metallurgy ke teen steps sahi tarteeb me kaunse hain?
Q5. Carbonate ore ko hawa ke bina garam karke oxide banane ki process ko kya kehte hain?
Q6. Ionic compounds solid state me current conduct nahi karte, lekin pighli hui avastha (molten) ya solution me conduct karte hain — iski wajah kya hai?
Q7. Amphoteric oxide ka udaharan kaunsa hai jo acid aur base dono ke saath react karta hai?
Q8. Iron ki frying pan ko rusting se bachane ka sabse achha tarika kya hai (kyunki wo baar-baar dhoyi jaati hai aur garam hoti hai)?
Q9. Copper aur AgNO3 (silver nitrate) solution ke beech reaction hoga ya nahi, aur kyun?
Q10. Sulphur ko jalane par nikalne wali gas (SO2) geele litmus paper ka rang kaisa kar degi?
Aksar Poochhe Jaane Wale Sawaal
Class 10 Science Chapter 3 me kitne questions hain?
Is chapter me 16 in-text questions aur 16 exercise questions hain — total 32 questions, jinke solutions upar diye gaye hain.
Reactivity series yaad karne ka aasan tarika kya hai?
K > Na > Ca > Mg > Al > Zn > Fe > Pb > H > Cu > Hg > Ag > Au. Sabse zaroori baat — hydrogen se upar wale metals hi dilute acid se hydrogen gas nikal sakte hain, neeche wale nahi.
Calcination aur roasting me kya farak hai?
Calcination me carbonate ore ko hawa ki anupasthiti me garam kiya jata hai. Roasting me sulphide ore ko hawa ki upasthiti me garam kiya jata hai. Dono ka maksad ore ko oxide me badalna hai, kyunki oxide ko reduce karna sabse aasan hai.
Aqua regia kya hai?
Aqua regia 3 bhaag concentrated hydrochloric acid aur 1 bhaag concentrated nitric acid ka mishran hai. Ye gold aur platinum ko bhi ghol sakta hai, isliye ise 'royal water' kaha jata hai.
Amphoteric oxides kaunse hote hain?
Wo metal oxides jo acid aur base dono ke saath react karke salt aur paani banate hain. Sabse aam udaharan aluminium oxide (Al2O3) aur zinc oxide (ZnO) hain.
Chapter 3 board exam ke liye kitna important hai?
CBSE chapter-wise weightage officially publish nahi karta. Ye chapter content ke hisaab se sabse bada hai - reactivity series, metallurgy ke teen steps aur corrosion har taraf kaam aate hain.
Class 10 Science — Saare Chapters
Board exam tak sirf revision karna hai?
Class 10 Science ke saare chapters ke colour handwritten short notes — diagrams, formulas aur important points ek jagah.
NCERT Kaksha ek swatantra shaikshik platform hai aur NCERT ya CBSE se aadhikarik roop se sambaddh (officially affiliated) nahi hai. Kisi galti ki jaankari dene ke liye contact kijiye.