Question

It was Paheli’s birthday, her brother Simba was helping her to decorate the house for the birthday party and their parents were also busy making other arrangements. Following were the activities going on at Paheli’s home: (i) Simba blew balloons and put them on the wall. (ii) Some of the balloons got burst. (iii) Paheli cut colorful strips of paper and put them on the wall with the help of tape. (iv) She also made some flowers by origami (paper folding) to decorate the house. (v) Her father made dough balls. (vi) Mother rolled the dough balls to make puries. (vii) Mother heated oil in a pan. (viii) Father fried the puries in hot oil. Identify the activities at Paheli’s home as those that can be reversed and those which cannot be reversed.

Answer 1

Reversible change:-

1. It is actually a change which can be undone or can be reversed.
2. This reversible change might change how a material will look or feel like, but it will not create any new material.
3. Example of reversible change:- Melting of wax, freezing of ice etc.
4. Therefore, among the above the activities that can be reversed are:

(i) Simba blew balloons and put them on the wall.

(iv) She also made some flowers by origami (paper folding) to decorate the house.

(v) Her father made dough balls.

(vi) Mother rolled the dough balls to make puries.

(vii) Mother heated oil in a pan.

Irreversible change:-

1. It is actually a chemical change that can not be reversed.
2. These are the permanent changes, and after the reaction as a product a new compound is formed and it can not be reversed.
3. Example:- Burning of a piece of paper, cooking of the raw egg.
4. Therefore, among the above the activities that can not be reversed are:

(ii) Some of the balloons got burst.

(iii) Paheli cut colorful strips of paper and put them on the wall with the help of tape.

(viii) Father fried the puries in hot oil.