Three States of Matter

Are you familiar with the three states of matter, solid, liquid and gas? Let's see what is in a solid. A solid is made up of particles known as molecules packed closely together. The forces between the molecules are so strong that the molecules cannot move freely but only vibrate. As a result, a solid has a stable, definite shape and a definite volume. A solid can only change its shape by force, that is ,when it is broken or cut. Solids can be transformed into liquids by melting and liquids can be transformed into solids by freezing. Solids can also change directly into gases through the process of sublimation.

A liquid is a nearly incompressible fluid that takes the shape of its container but keeps an almost constant volume independent of pressure. When a solid is heated above its melting point, it becomes liquid.

A gas is a compressible fluid. Not only will a gas fit in with the shape of its container but it will also expand to fill the container. A gas has no definite shape or volume, but occupies the entire container in which it is kept. A liquid may be converted to a gas by heating at constant pressure to the boiling point or by reducing the pressure at constant temperature.

Test Your Science

1. At which state(s) does matter have no definite shape?

Read about the three states of a candle in the Young Scientists Issue 113 Level 2.