Dry ice is :

Silica is:

In Moh's scale of hardness, Diamond is given the value:

The element having lowest  melting point is:

Solder consists of:

An alloy of carbon which has a spherical molecule made of 60 carbon atoms covalently bonded together is called:

The modern periodic table is classified on the basis of:

The structure of methane is:

Group VII elements are called:

Mixtures of elements designated to have properties that are useful for a particular purpose: