Matter and its Properties
Concept: Solids, Liquids and Gases
Matter can exist in one of the following states—solids, liquids and gases. Let us look at the characteristic features of these three states of matter.
- Solids are materials that can retain their shapes and volumes.
- Solids have the following properties—
- Their shapes, sizes and volumes are fixed.
- The molecules in solids are packed closely.
- Molecules in solids are not free to move in any direction. They only vibrate in their fixed positions.
- The force of attraction between the molecules of a solid are very strong
Example: Stone, wood, walls, buildings, bottles, chairs, books etc.
- Liquids are materials that can retain only their volumes but not their shapes.
- Liquids have the following properties—
- They do not have a shape of their own and take the shape of the container they are poured in.
- The molecules in liquids are loosely packed and can move freely.
- The arrangement of the molecules in a liquid allows them to assume the shape of their containers.
- The force of attraction between the molecules of a liquid is moderate.
Examples:Oil, water, juice, etc.
- Gases are materials that have no definite shape, size and volume.
- Gases have the following properties—
- They do not have a shape of their own and occupy the available space. It could be as small as a container or as large as a tank.
- The molecules in gases are very loosely packed and can move freely.
- There is essentially no force of attraction between the molecules of a gas.
- The molecules in a gas can be compressed and brought closer enough to convert them into the liquid state. LPG is an example.
Examples: Oxygen, carbon dioxide, air, hydrogen, water vapour, etc.
Liquids and gases can be used as solvents, but solids cannot solubilise any solute. The reason is that gases and liquids have intermolecular spaces occupied by the solute molecules. However, solids do not have any intermolecular space to accommodate the solute molecules. Now can you imagine the solute and the solvent in the lemonade?
Compressed: To make something fill less space than usual by bringing the molecules/atoms close by external means.
LPG: It stands for Liquefied Petroleum Gas. It is a fuel consisting of several gases in liquid form.
Did You Know?
Apart from the three states of matter that you have read, there is a fourth state called plasma. This state of matter exists in fire flames, lightning, and the polar auroras.