Chlorine is an element. Air is a mixture whereas water and sulphur dioxide are examples of compounds.

Water is a compound.

Glass is made of sodium, silicon and oxygen.

The symbol for potassium is K.

Marble is an example of compound.

Plasma is a fourth state of matter, which has the highest kinetic energy.

Sulphur is a polyatomic element.

As oxygen is a gas and gases are highly compressible in nature.

Mixture of NaCl and water can be separated by distillation as distillation is a process of separating the component substances from a liquid mixture by selective evaporation and condensation.

The balloon bursts with a sound when it is pricked with a needle because of the force exerted by the gas present in the balloon.

Mixture of sand and water can be separated by the methods of sedimentation and decantation.

From all the given options, diamond is an element.

Chemical formula for water glass is Na₂SiO₃.

A compound is made of elements X and Y. The equivalent weight of X is one-fourth its atomic weight and the equivalent weight of Y is half its atomic weight. Therefore, the formula of the compound is XY₂.

Dead burnt plaster is CaSO₄.

In the formula for aluminium chloride Al_aCl_b, the respective values of a and b are 1 and 3 (i.e. AlCl₃).

Chemical name of ‘blue vitriol’ is copper sulphate.

When iron filings are heated in a steam of dry hydrogen chloride, the compound formed is FeCl₂.

The formula for ferric sulphate is Fe₂(SO₄)₃.

The molecular formula of glucose is C₆H₁₂O₆.