Properties of Metals - Physical and Chemical Properties
Physical properties
1. Physical state: All metals are solids at room temperature except mercury and gallium.
2. Lustre: Metals possess a high lustre (called metallic lustre).
3. Hardness: Most of the metals are hard and strong (exceptions: sodium and potassium can be cut with a knife)
4. Melting point and Boiling point: Usually, metals possess high melting and boiling points and vaporize only at high temperatures (exceptions: gallium, mercury, sodium and potassium).
5. Density: Metals have a high density (exceptions: sodium and potassium are less dense than water).
6. Ductility: Metals are usually ductile. In other words, they can be drawn into thin wires without breaking.
7. Malleability: Metals are usually malleable, i.e, they can be beaten into thin sheets without cracking (except zinc and mercury).
8. Conduction of heat and electricity: Metals are good conductors of heat and electricity; silver and copper excel in this property (exception: tungsten)
9. Solubility: Usually, metals do not dissolve in liquid solvents.
Chemical Properties
1. Valence electrons: Atoms of metals usually have 1,2 or 3 electrons in their outermost shell.
2. Formation of ions: Metals form Positive ions by the loss of electrons and hence they are electro positive.
3. Discharge of ions: Metals are discharged at the cathode during the electrolysis of their compounds.
4. Atomicity: Molecules of metals in their vapour state are usually monoatomic.
5. Nature of oxides: Oxides of metals are usually basic.