Nonmetals are those elements which do not exhibit the properties of metals.
Physical Properties of Non-metals
- Occur as solids, liquids and gases at room temperature
- Brittle
- Non-malleable
- Non-ductile
- Non-sonorous
- Bad conductors of heat and electricity
Exceptions in Physical Properties
- Alkali metals (Na, K, Li) can be cut using a knife.
- Mercury is a liquid metal.
- Lead and mercury are poor conductors of heat.
- Mercury expands significantly for the slightest change in temperature.
- Gallium and caesium have a very low melting point.
- Iodine is non-metal but it has lustre.
- Graphite conducts electricity.
- Diamond conducts heat and has a very high melting point.
Examples of Non-metals
- Hydrogen – Gas
- Nitrogen – Gas
- Oxygen – Gas
- Fluorine – Gas
- Chlorine – Gas
- Bromine – Liquid
- Iodine – Solid
- Carbon – Solid
- Sulphur – Solid
- Phosphorous – Solid
- Silicon – Solid