Circle the odd one out on the basis of the property given in the brackets.

(a) hydrogen, nitrogen, chlorine, phosphorus (state)

(b) sodium, potassium, iron, lithium (hardness)

(c) graphite, diamond, iodine, coal (forms of a same element)

(d) helium, neon, argon, bromine (reactivity)

Name:

(a) Three different forms of carbon.

(b) A form of carbon used as a gem.

(c) Two substances used to make electric wires.

(d) Two substances used to make jewellery.

(e) A substance used as an insulator.

Give reason:

A frying pan is made up of steel but its handle is made up of wood.

Give reason:

Graphite is used to make lead of the pencils.