Elements can be divided into

metals

non-metals

Aluminium is a typical metal

Chlorine is a gas at room temperature and pressure.

All metals are:

1. Shiny (lustrous).

2. Good thermal and electrical conductors.

3. Malleable (can be flattened without breaking).

4. Ductile (can be pulled out into wire).

Light bulb filament

Aeroplane

Metals are ductile.

Metals are malleable

Note:

Most metals are hard, dense and possess high melting points.

Exceptions:

(a) sodium is a soft solid with rather low m.p. (100oC)

(b) mercury is a liquid at room temperature.

Gate

The non-metals have properties that are almost opposite to those of metals. They are

1. dull

2. poor thermal and electrical conductors.

3. not malleable

4. not ductile.

Note:

1. Carbon (graphite only) can conduct electricity.

2. Many non-metals are gases at room temperature.

Example:

oxygen, hydrogen, nitrogen, chlorine, neon, etc.

Bromine is a liquid at room temperature.

They are silicon, boron.

Their properties are between those of metals and non metals.

Metalloids are usually shiny but brittle.

They do not conduct electricity very well.