(a) What are the

(a) We can change the physical state of matter in two ways:

(i) By changing the temperature (heating or cooling).

(ii) By changing the pressure (increasing or decreasing the pressure).

These two factors decide whether a given substance would be in a solid, liquid or gaseous state.

(b)

(c) The rate of evaporation of a liquid can be made faster by

(i) Increasing the temperature

(ii) Increasing the surface area of the liquid

(iii) Lowering humidity and

(iv) increasing wind speed.