Non-Metals

Question 1 Name one non-metal which conduct electricity?

Question 2 Name one non-metal which have shiny surface?

Question 3 Name one non-metal which is hard?

Question 4 Name one non-metal having high melting point?

Question 5 Why graphite is used in making electrodes?

Question 6 Name one non-metal which is brittle?

Question 7 Name one non-metal which has low melting point?

Non-Metals

For Example: Carbon, sulphur, phosphorus, silicon, hydrogen, oxygen, chlorine, bromine, iodine, helium etc.

Non-Metals are elements which form negative ions by gaining electrons. They are known as electronegative elements because they can form negative ions by gaining electrons.

There are 22 non-metals.

1) 10 solids

2) 1 liquid (bromine)

3) 11 gases

Physical Properties of Metals

1) Non-metals are not malleable and non-ductile.

They can neither be hammered into thin sheets nor drawn into thin wire.

They are brittle means break into pieces when hammered or stretched.

For Example :Sulphur, phosphorus.

2) They do not conduct heat and electricity

This is because they have no free electrons.

C (in the form of graphite) is the only non-metal which is a good conductor of heat and electricity and therefore it is used in making electrodes.

3) They are not lustrous: They are dull.

Iodine is the only non-metal which is lustrous.

4) They are generally soft except diamond (hard)

5) They are not strong: They can be easily broken.

6) Non-metals are solid, liquid or gases at the room temperature.

Carbon, Sulphur, Phosphorus are solid.

Bromine is a liquid.

Hydrogen, oxygen, nitrogen and chlorine are liquid.

7) They have low melting and boiling point except diamond.

8) They are non-sonorous.

9) They have low densities.

10) They have different colours.