Metals mein jang kyun lagta hai?

Iron pe bhoori parat

Kuch din khule mein padi iron ki cheezon pe aksar bhoori parat jam jaati hai. Ye hawa se hai, paani se, ya dono se? Activity 4.5 ek nishpaksh jaanch karti hai.

Teen bottle ka prayog

Teen chamakdaar iron ki keelein, zaroorat ho to sandpaper se saaf karke, dhaage se baandhkar teen saaf, sookhi bottlon A, B aur C mein rakhi jaati hain:

• Bottle A mein keel aur thoda silica gel hai, aur dhakkan kaskar band hai. Silica gel hawa ko sookha karta hai, jaise iski chhoti potliyan dawa ki bottle aur jooton ke dibbon ko sookha rakhti hain. Yaani is keel ko sirf sookhi hawa milti hai.
• Bottle B mein keel poori tarah taaza ubaale aur thande kiye paani mein doobi hai, jisse ghuli hawa nikal gayi hai, aur upar tel ki parat hai taaki hawa phir na ghule. Dhakkan kaskar band hai. Yaani is keel ko sirf paani milta hai.
• Bottle C mein keel aadhi paani mein doobi hai aur bottle khuli hai, yaani is keel ko hawa aur paani dono milte hain.

Bottlein room temperature pe 8 se 10 din bina chhede rakhi jaati hain.

Bottlein kya dikhati hain

A aur B ki keelon pe koi bhoori parat nahi aati, yaani sirf sookhi hawa aur sirf paani se ye nahi banti. Sirf bottle C ki keel, jise dono mile, pe bhoori parat jamti hai. Yaani hawa aur paani dono, yaani nam hawa, zaroori hain. Bhoori parat jang (rust) hai, aur iron ki cheezon pe jang banne ki prakriya rusting hai.

Doosre metals ka corrosion

Khuli hawa mein sirf iron nahi badalta. Copper ki cheezon pe hari parat, aur chaandi ke gehno aur bartano pe kaali parat aati hai. Hawa, paani ya doosre padaarthon se metal ki sateh ka dheere-dheere kharaab hona corrosion kehlaata hai; rusting iron ka corrosion hai.

Jang se bachaav

Bharat mein rusting ek gambhir samasya hai: har saal jang se kharaab iron ke dhaanchon ki marammat ya badalne mein bahut paisa lagta hai. Jang ke liye hawa aur paani dono chahiye, isliye bachaav ka tareeka hai unhe iron se door rakhna: paint, tel (oiling) ya grease lagaakar, ya zinc metal ki patli suraksha parat chadhaakar, jise galvanisation kehte hain. In tareekon ke baare mein aage ki kakshaon mein aur padhoge.

Delhi ka Iron Pillar

Prachin Bharatiya dhaatu kaarigar aisa iron banaana jaante the jo jang se bacha rahe. Delhi ka Iron Pillar Chandragupta II ke samay, 1600 se zyaada saal pehle, bana tha. Ye lagbhag 8 metre ooncha hai aur iska vajan 6000 kilogram se zyaada hai, aur sadiyon ki hawa, baarish aur kathor mausam ke baad bhi is pe na ke barabar jang hai.

Ye kyun zaroori hai

Pul, rail ki patriyan, jahaaz, auzaar aur gate iron ke hote hain, isliye jang rokna paisa bachaata hai aur logon ko surakshit rakhta hai. Metals ke baaki gun metals aur non-metals ki properties mein, aur metals aur non-metals oxygen se kaise reaction karte hain, ye metal aur non-metal oxides mein hai. Har activity aur sawaal ka jawab Chapter 4 ke NCERT solutions mein hai; poore Chapter 4 ke notes bhi dekho.