Class 7 Science Chapter 4: The World of Metals and Non-metals (Hinglish Notes)
Ye chapter 5 lines mein
The World of Metals and Non-metals elements ke do samoohon ki tulna karta hai. Iron, copper aur aluminium jaise metals aam taur pe chamakdaar, sakht, malleable, ductile aur sonorous hote hain, garmi aur bijli achhe se guzaarte hain, aur basic oxide banaate hain. Sulfur jaise non-metals dhundhle, bhurbhure aur kharaab conductors hote hain, aur acidic oxide banaate hain. Nam hawa mein iron ko jang lagta hai.
Ye chapter kis baare mein hai?
School project ke liye Yashwant aur Anandi apne Rajasthan ke gaon ke lohaar Sudarshan se milne jaate hain. Ve iron se tawa, baalti, chimta, phawda, kulhaadi, khurpi aur jelee banaate hain, lakdi ke handle lagaate hain, aur iron ko coal ki bhatti mein garam karte hain. Jab ve laal garam iron ke tukde ko peetkar kulhaadi ka aakaar dete hain, to Anandi ke mann mein sawaal aata hai ki kya doosre metals bhi aise chapte kiye ja sakte hain. Chapter dekhta hai ki metals kya-kya kar sakte hain, hawa aur paani se kaise reaction karte hain, aur non-metals kaise alag hain.
Chamak aur sakhti
Copper, aluminium, iron, coal, sulfur aur lakdi ke tukdon ko hathode se peetne pe saaf farq dikhta hai. Copper, aluminium aur iron chamakdaar (lustrous) aur sakht hain: ye metals hain, aur inki chamak metallic lustre kehlaati hai. Coal, sulfur aur lakdi dhundhle aur utne sakht nahi. Par har metal sakht thos nahi: sodium aur potassium itne naram hain ki chaaku se kat jaate hain, aur mercury room temperature pe drav hai.
Chaadar, taar aur aawaaz
Peetne pe metals chaadar ban jaate hain. Ye malleability hai: mithaai pe chaandi ka warq aur khaana lapetne ki aluminium foil isi se bante hain, aur gold aur chaandi sabse zyaada malleable metals hain. Coal aur sulfur tukdon mein toot jaate hain, isliye ve bhurbhure (brittle) hain, aur lakdi na chapti hoti hai na toot-ti hai. Metals kheenchkar taar bhi bante hain, ye ductility hai: bijli ke taar, kangan, veena ya sitar ke taar, aur pulon aur cranes ki steel ki rassiyan isi pe tiki hain. Gold itna ductile hai ki ek gram se lagbhag 2 km lamba taar ban sakta hai. Metals sonorous bhi hain: girta chammach ya sikka khanakta hai, school ki ghanti aur ghungroo bhi, jabki coal aur lakdi bas dhap karte hain. Aur padho metals aur non-metals ki properties mein.
Iron ne Bharat ka itihaas badla. Harappa ke log auzaaron aur gehno ke liye copper aur gold use karte the, par iron lagbhag nahi, jo rozmarra ke kaam mein bahut baad mein aaya. Jab aaya, to iron ke mazboot hal aur auzaar pehle waalon se kahin behtar the aur sabhyata ko aage badhaaya.
Garmi aur bijli ke conductors
Garam paani mein metal ka chammach aur lakdi ka chammach rakho, to sirf metal waale ka upari sira garam hota hai: metals garmi ke achhe conductors hain, isliye bartan metal ke aur unke handle lakdi ya plastic ke hote hain. Tester circuit mein aluminium foil, iron ki keel aur copper ka taar bulb jalaate hain, jabki sulfur, coal, lakdi, patthar, rubber aur nylon nahi. Metals bijli ke achhe conductors hain; rubber ke dastaane aur plastic ke handle electricians ko bachaate hain kyunki ve kharaab conductors hain.
Jang aur corrosion
Teen iron ki keelein poori kahaani batati hain. Sookhi hawa waali keel ko jang nahi lagta, na hi ubaale paani mein tel se band keel ko, par khuli bottle mein aadhi paani mein dubi keel pe bhoori parat jam jaati hai. Iron ko jang tabhi lagta hai jab hawa aur paani dono milein. Bhoori parat jang (rust) hai, aur iska banna rusting. Doosre metals pe bhi corrosion hota hai: copper pe hari aur chaandi pe kaali parat. Paint, tel, grease aur galvanisation, yaani zinc ki parat, iron ko bachaate hain. Delhi ka Iron Pillar, jo 1600 se zyaada saal pehle bana, us pe na ke barabar jang hai. Padho metals mein jang kyun lagta hai.
Metals aur non-metals ke oxides
Magnesium ka ribbon chaundhiya dene waali safed lau se jalta hai aur safed powder, magnesium oxide, ban jaata hai. Iska ghol laal litmus ko neela karta hai, isliye ye basic hai: metals ke oxides aam taur pe basic hote hain. Sodium oxygen aur paani se itna tez reaction karta hai ki use kerosene mein rakha jaata hai. Sulfur jalkar sulfur dioxide banaata hai, jo paani mein ghulkar sulfurous acid banaati hai aur neele litmus ko laal karti hai: non-metals ke oxides acidic hote hain. Padho metal aur non-metal oxides.
Hamaare jeevan mein non-metals
Sulfur aur phosphorus jaise non-metals aam taur pe naram aur dhundhle hote hain, na malleable na ductile, khanakte nahi, aur kharaab conductors hain; phosphorus hawa mein aag pakad leta hai, isliye paani mein rakha jaata hai. Inke bina hum jee nahi sakte: hum oxygen saans mein lete hain, carbon har jeev ki neenv hai, nitrogen se khaad banti hai, chlorine paani saaf karti hai aur iodine antiseptic hai. Metals aur non-metals elements hain, jinme lagbhag 118 jaane jaate hain; plastic, kaanch, lakdi, rubber aur kaagaz elements nahi hain. Kai metals aur steel jaise alloys aaj ki industry chalaate hain, aur Bharat mein iron aur aluminium recycle kiye jaate hain.
Saar mein
Metals aur non-metals dikhne, chhoone, aawaaz aur conduction mein, aur hawa aur paani se reaction mein alag hain, aur yahi gun unke upyog tay karte hain. Har activity, Table 4.1 se 4.3 aur baarah sawaalon ke jawab Chapter 4 ke NCERT solutions mein hain.
Key terms (zaroori shabd)
| Term | Matlab |
|---|---|
| Metal | Iron, copper, aluminium ya gold jaisa element jo aam taur pe chamakdaar aur sakht ho, patli chaadar aur taar ban sake, aur garmi aur bijli achhe se guzaare. |
| Non-metal | Sulfur, carbon, oxygen ya phosphorus jaisa element jo aam taur pe dhundhla, naram ya bhurbhura ho, aur garmi aur bijli ka kharaab conductor ho. |
| Metallic lustre | Metals ki chamak, jaise naye copper ke sikke ya saaf iron ki keel pe. |
| Malleability | Peetkar patli chaadar banne ka gun, jaise aluminium foil ya mithaai pe chaandi ka warq. |
| Brittle (bhurbhura) | Hathode se peetne pe tukdon mein toot jaana, jaise coal aur sulfur. |
| Ductility | Kheenchkar taar banne ka gun; ek gram gold se lagbhag 2 kilometre lamba taar ban sakta hai. |
| Sonority | Metals ka takraane pe khanakti aawaaz dena, jaise ghanti aur ghungroo. |
| Conductor | Wo padaarth jo garmi ya bijli ko aasaani se guzarne de. Metals achhe conductors hain; lakdi, rubber aur plastic kharaab. |
| Rusting (jang lagna) | Iron pe bhoori parat, jang, ka banna, jab wo hawa aur paani dono ke sampark mein ho. |
| Corrosion | Hawa, paani ya doosre padaarthon se metal ki sateh ka dheere-dheere kharaab hona, jaise copper pe hari aur chaandi pe kaali parat. |
| Galvanisation | Jang se bachaane ke liye iron pe zinc metal ki patli parat chadhaana. |
| Element | Aisa padaarth jise aur saral padaarthon mein toda na ja sake. Lagbhag 118 jaane jaate hain, aur metals aur non-metals elements hain. |
Is chapter ke topics
Practice karo
-
Aluminium ki foil kis gun se banti hai?
Jawab dekho
Jawab: (b) Malleability
-
Room temperature pe kaunsa metal drav hai?
Jawab dekho
Jawab: (b) Mercury
-
Khaana pakaane ke bartan metal ke kyun hote hain?
Jawab dekho
Jawab: (b) Metals garmi ke achhe conductors hain
-
Iron ko jang lagne ke liye kya chahiye?
Jawab dekho
Jawab: (c) Hawa aur paani dono
-
Magnesium oxide ki prakriti kya hai?
Jawab dekho
Jawab: (b) Basic
-
Inme se kaunsa element nahi hai?
Jawab dekho
Jawab: (c) Kaanch
Students ke sawal
Class 7 Science Chapter 4 ke mukhya topics kya hain?
Wo gun jo metals ko alag banaate hain: chamak, sakhti, malleability, ductility, sonority aur garmi aur bijli ka conduction. Phir iron ka jang lagna, doosre metals ka corrosion aur inse bachaav; magnesium aur sulfur ko jalaana aur unke oxides ki prakriti; non-metals metals se kaise alag hain aur kyun zaroori hain; aur elements kya hain.
Kya The World of Metals and Non-metals nayi NCERT Class 7 Science kitaab mein hai?
Haan. Ye Curiosity, Class 7 Science ki kitaab (Reprint 2026-27) ka Chapter 4 hai, pages 41 se 56 tak. Iski shuruaat mein Rajasthan ke ek gaon ke do vidyaarthi, Yashwant aur Anandi, Sudarshan naam ke lohaar se milne jaate hain, jo laal garam iron ko peetkar kulhaadi, tawa aur kheti ke auzaar banaate hain.
Metals aur non-metals mein kya farq hai?
Metals aam taur pe chamakdaar, sakht, malleable, ductile aur sonorous hote hain, aur garmi aur bijli achhe se guzaarte hain; unke oxides basic hote hain. Non-metals aam taur pe dhundhle aur naram ya bhurbhure hote hain, chaadar ya taar nahi bante, khanakte nahi, aur garmi aur bijli kharaab guzaarte hain; unke oxides acidic hote hain aur ve aam taur pe paani se reaction nahi karte.
Delhi ke Iron Pillar ko jang kyun nahi laga?
Chandragupta II ke samay, 1600 se zyaada saal pehle, bana ye stambh aise tareeke se banaaya gaya ki jang se bacha rahe, jo prachin Bharatiya dhaatu kaarigaron ke hunar ko dikhata hai. Sadiyon ki hawa aur baarish ke baad bhi is pe na ke barabar jang hai. (Extra: adhyayan bataate hain ki iske iron mein maujood phosphorus sateh pe ek patli suraksha parat banaane mein madad karta hai.)
Koi sawal atak gaya?
Photo lo, Lagnever AI step-by-step samjhayega. 7 din ka trial sirf ₹2.
Google Play se app lo Browser mein kholo
Parents ke liye: trial ke baad plan har mahine UPI ya card autopay se renew hota hai. App mein kabhi bhi cancel kar sakte hain.