Solution 2 ( Physical and Chemical Changes)

A change in which one or more new substances are formed is called chemical change. It is also known as chemical reaction.

Eg:- Medicines, plastic, detergent etc are produced by chemical change.

In addition to new products other changes can occurs in a chemical change which are given below:

(i)Heat, light or any other radiation may be given off or absorbed.

Eg:-Burning of any substance

(ii) Sound may be produced.

Eg:- Explosion of fireworks that produces light, heat, sound and gases.

(iii)A change in smell may take place or a new smell may be given off.

Eg:-Rotten food items produce smell.

(iv) A colour change may take place.

Eg:- colour of apple, potato and brinjal slice changed to brown if it is not consumed immediately.

(v) A gas may be formed.

Eg:- Explosion of fireworks, candle flame produces gas.

Previous solution

Next solution

Helping Topics

Physical and chemical changes

Effect of Magnesium hydroxide on litmus paper

Physical and Chemical changes of a burning candle

Physical and chemical changes of making paper 

Burning of wood and cutting it into small pieces are considered as two different types of changes

Rusting of iron objects is faster in coastal areas than in deserts

Identification of Physical and Chemical changes in different processes

NCERT solutions class 7

Picture1

Leave a comment