Question

[TBQ.X.(3)]
Boiling of water is a physical change; but boiling of egg is a chemical change. Why?

Answer 1

Chemical change is a change in which one or more substances are formed.

Boiling of water is a physical change:

On boiling, water is converted into steam. If we cover the beaker with a lid, steam condenses back to water. So, boiling, of water is a physical change since only the physical state of water changes.

Boiling of egg is chemical change:

When egg is boiled, chemical nature of the egg changes as new substances are formed. The properties of a boiled egg are totally different from the raw egg. Hence, boiling of an egg is a chemical change.