Matter : a physical substance that occupies space and has mass called matter.
- Matter is made up of atoms and molecules.
Atoms are the basic unit of matter and the defining structure of elements.
The structure of atoms is made up of a central nucleus, which is composed of protons and neutrons, surrounded by electrons.
Molecules are formed when two or more atoms are bonded together chemically.
Matter can exist in three main states:
- solid,
- liquid,
- gas.
The state of matter depends on the temperature and pressure of the substance.
Solids have a fixed shape and volume, liquids take the shape of their container but have a fixed volume, and gases take the shape and volume of their container.