Non-metals and their general properties

NON-METALS AND THEIR GENERAL PROPERTIES

Non-metals are present on the right hand side of the periodic table (except Hydrogen).

PHYSICAL PROPERTIES OF NON-METALS:

The important physical properties of non-metals are listed below:

• Non-metals are brittle.
• Non-metals are not ductile.
• Non-metals are bad conductor of heat and electricity.

• Non-metals are not lustrous and-cannot be polished.

• Non-metals may be solid, liquid, or gases at room temperature. Solid: Carbon, sulphur and iodine.

Gases : Oxygen, hydrogen, nitrogen etc.

Bromine is the only non-metal which exists as a liquid at room temperature.

Liquid non-metal : Bromine

Non-metals have generally low melting and boiling points.

Exception: Graphite, another allotropic form of Carbon, has a melting point of about 3730°C. Other exceptions are C, B, Si which have high melting and boiling points.

Non-metals have low densities.

Exception: Iodine has high density and diamond which is almost as heavy as AI.

Malleability : Non-metals are not malleable i.e. sheets cannot be made from non-metals.

Tensile strength : Non-metals do not have the property of tensile strength.

Exception: Carbon fibre is as tensile as steel.

Sonorous : Non-metals are non-sonorous, i.e., when struck with a hammer they do not produce sound.

Colour : Chlorine is a greenish yellow gas, while bromine is brown in colour. Iodine is violet in colour, while oxygen and nitrogen are colourless gases.

DIFFERENCES IN PHYSICAL PROPERTIES OF METALS AND NON-METALS: