Metals and Non - metals
There are about 118 elements, from which 92 are naturally occurring. Metals and non-metals are characterized by their physical and chemical properties.
Characteristics of Metals
- Metals have tendency to lose electrons.
- Metals are strong and tough.
- Metals have high melting and boiling point.
- Most of the metals are malleable or can be changed into thin sheets. For example, aluminium can be drawn into thin sheets.
- Metals are ductile or can be drawn out into thin wires. For example, copper can be drawn into wire.
- Metals are good conductor of electricity and heat.
- Metals are solids at room temp except mercury, which is a liquid.
- Metals are lustrous.
- Metals tend to have low ionization energies. In other words they gets oxidized when they undergo chemical reactions.
- Metals from compounds with non – metals that are ionic in nature.
- Most metal oxides are basic oxides. They dissolve in water to form metal hydroxides.
- Metal oxides exhibit their basic chemical nature by reacting with acids to form salts ice water:
Characteristics of Non Metals
- Non- metals have tendency to gain electrons.
- Non- metals are brittle. They are neither malleable nor ductile.
- Non -metals are non- lustrous.
- Non -metals are poor conductors of heat and electricity.
- Non- metals have melting point lower than metals.
- Non- metals, gain electrons or reacting with metals to attain noble gas electrons configuration and become anions.
- Most non -metal oxides are acidic oxides. These acidic oxides dissolve in water to form acids.
- Non -metal oxides can combine with bases to form salt and water.
Metalloids have properties intermediate between the metals and non- metals. Silicon for example appears lustrous, but is neither malleable nor ductile but is brittle which the characteristic of some non -metals. Metalloids are also useful in the semi- conductor industry.