Adhaatu aur Unke Upyog

Class 7 Science · Chapter 4: Dhaatu aur Adhaatu ki Duniya · NCERT Curiosity section 4.4–4.5

Seekho

Teacher dhake jar mein chammach mein gandhak jalaati hain (hawadaar jagah mein: gas haanikaarak). Jar mein paani hilaane se gas, sulfur dioxide, ghulkar sulfurous acid banaati hai: neela litmus laal. Adhaatuon ke oxide acidic. Paani mein gandhak ka powder kuch nahi karta: adhaatu aam taur par paani se kriya nahi karte.

sulfur + oxygen → sulfur dioxide (acidic in water)

Gandhak aur phosphorus adhaatu hain: aam taur par naram aur feeke, na malleable na ductile, na khanakte, aur garmi-bijli ke kharaab chaalak. Phosphorus hawa mein aag pakadta, isliye paani mein rakha jaata. Oxygen, hydrogen, nitrogen aur carbon bhi adhaatu.

Dhaatu aur adhaatu tatva hain: jo saral padaarthon mein na toot sakein (118 gyaat). Plastic, kaanch, lakdi, rubber aur kaagaz tatva nahi, isliye na dhaatu na adhaatu. Dhaatuon ka, ya dhaatu aur adhaatu ka mishran (jaise steel: loha aur carbon) mishr-dhaatu (alloy) hai.

Adhaatu zaroori hain: hum oxygen saans mein lete; carbon protein, vasa aur carbohydrate banaata; nitrogen khaad mein; chlorine paani saaf karti; iodine ka ghol antiseptic. Bharat bahut sa loha aur aluminium recycle karta, sansaadhan bachaata.

Explore: dhaatu, adhaatu ya dono nahi?

1. Har ek sort karo.

Yaad rakho

• Adhaatu feeke, bhangur, kharaab chaalak aur acidic oxide banaate.
• Oxygen, carbon, nitrogen, chlorine aur iodine zaroori adhaatu.

Quick check

Adhaatu ka oxide paani mein ghulkar aam taur par …

1. acidic
2. basic
3. neutral
4. a metal

Socho

Dhaatuon aur adhaatuon ke gun unke upyog kaise tay karte?

Practice

Teen levels (easy, medium, hard) ke naye sawaalon se practice karo, kuch hands-on, hints aur hal ke saath. Topic poora karne ke liye pichhle 5 mein se 4 sahi karo.