State two physical properties on the basis of which metals can be distinguished form non-metals.
A detailed comparison of properties of metals and non-metals is given in table:
Property | Metals | Non-metals |
State of matter | These are usually solid, except mercury, which is a liquid at room temperature. Gallium and Caesium melt below 30. So if room temperature is around 30, they may also be in liquid state | These exist in all the three states. Bromine is the only liquid. |
Density | They usually have high density, except for sodium, potassium, calcium etc. | Their densities are usually low. |
Melting point | They usually have a high melting point except mercury, cesium, gallium, tin, lead. | Their melting points are low. |
Boiling point | Their boiling points are usually high. | Their boiling points are low. |
Hardness | They are usually hard, except mercury, sodium, calcium, potassium, lead etc. | They are usually not hard. But the exception is the non-metal diamond, the hardest substance. |
Malleability | They can be beaten into thin sheets. | They are generally brittle. |
Ductility | They can be drawn into thin wires, except sodium, potassium, calcium etc. | They cannot be drawn into thin wires. |