Three states of matter
Solids, liquids and gases are three states of matter. In solids, the particles are tightly packed together. In liquids, the particles have more movement, while in gases, they are spread out. Particles in chemistry can be atoms, ions or molecules.
It is important to understand the particle nature of matter. The particles that make up matter are not ‘small bits of solid’ or ‘small drops of liquid’ but atoms and molecules. The physical characteristics of those atoms and molecules decide its state.