Types of Elements: Non-metal

Physical properties of a non-metal:-

The non-metals are either solids or gases except bromine which is a liquid. carbon, iodine, sulphur, hydrogen, oxygen, mercury are some examples of non-metals.

Brittle:- Non-metals are usually Brittle in nature.

Dull:- Non metals are dull and donot have a shiny surface.

non malleable:- Non metals are brittle and therefore cannot be converted into thin sheets.

Non ductile:- Non metals cannot be drawn into wires.

poor conductivity:- Non metals are poor conductor of heat and electricity.

Non sonorous:- on-metal do not produces sound on striking a hard surface.

Exceptions:-

(i)All metals except mercury exist as solids at room temperature.metals have high melting points but gallium and caesium have very low melting points. These two metals will melt if you keep them on your palm.

(ii) Iodine is a non-metal but it is lustrous.

(iii) Carbon is a non-metal that can exist in different forms. Each form is called an allotrope. Diamond, an allotrope of carbon, is the hardest natural substance known and has a very high melting and boiling point. Graphite, another allotrope of carbon, is a conductor of electricity.

(iv) Alkali metals (lithium, sodium, potassium) are so soft that they can be cut with a knife. They have low densities and low melting points.