Chapter 3.2, Problem 11SSC

Interpretation Introduction

Interpretation:

The result of a physical change should be described, and three examples of the physical changes need to be explained.

Concept introduction:

The nature of any substance is explained by their chemical properties and physical properties.

Answer to Problem 11SSC

If there is zero changes in the composition of the substances and also, changes are reversible the change is considered as physical. For example −

1. Breaking a pencil in two is the example of physical change.
2. The freezing of water and changes into ice is a physical change.
3. The water boils at $\text{100}°\text{C}$, change into gas state.

Explanation of Solution

A physical property describes the physical changes of a substance. Physical change is a temporary change; it is a reversible change. For example, color, mass, volume, etc.

In the physical changes, the change is for a short duration. The physical change takes place with absorption (very little quantity) of the heat. In the physical changes, no production of energy takes place.

There are three examples of physical changes −

1. Breaking a pencil in two is the example of physical change because composition is remains same for both parts of the pencil.
2. The freezing of water and changes into ice is a physical change because there is change in state, composition remains constant.
3. The water boils at $\text{100}°\text{C}$, change into gaseous state. Water changes into vapors is the example of phase transfer.

Conclusion

The change in the state of matter is the example of physical changes, the ratio of the molecules remains constant, and no new atoms will be generated.