2. The glass used for making lens?
Answer :- Flint glass
3. Lens used in camera?
Answer :- Convex
4. The bomb dropped in Hiroshima?
Answer :-Little Boy
5. The bomb named Fatman was dropped in?
6. The sodium salt used for bleaching?
Answer :-Sodium peroxide
7. The product obtained when gypsum is heated in 125 degree Celcious?
Answer :- Plaster of Paris
8. The chemical used to make ink?
Answer :- Ferrous sulphate
9. Soil has red colour due to the presence of ?
Answer :- iron oxide
10. Dihydrogen oxide is the chemical name of?
Answer :- Water