Question

Give one example in each case
(a) Change which occurs on heating but can be reversed.
(b) Change which occurs on heating but cannot be reversed.
(c) Change which occurs on cooling but can be reversed.
(d) Change which occurs on mixing two substances, but can be reversed.
(e) Change which occurs on mixing two substances, but cannot be reversed.

Answer 1

(a) Heating of an iron rod.
(b) Baking of chapati.
(c) Formation of ice from water.
(d) Formation of salt solution.
(e) Mixing of cement and water.