All materials can be grouped or classified. The simplest way of grouping materials is whether they are a solid, a liquid or a gas. It is also possible to sort materials according to their proprerties:
- Absorbency: how easily a material will absorb or repel liquids
- Conductivity: the ability of a material to conduct electricity and/or heat.
- Density: a measure of the mass of a material per unit of volume which determines whether a material will sink or float in a liquid. An ice cube is less dense than water so floats whereas a stone is more dense so sinks. You can read about the other factors that affect floating and sinking here.
- Elasticity: how easily a naterial returns to its original size and shape after being stretched or compressed.
- Flexibility: how bendable a material is.
- Hardness: how easily a material can be cut or scratched.
- Flammability: how easily a material can be ignited or set alight.
- Malleability: how easily a material can be shaped or moulded.
- Strength: How easily or how much force is needed to break a material.
- Transparency: How nuch light is let through. You can read more about transparent, translucent and opaque materials here.