Select the odd one out from the following:

(a) Salt solution, sugar solution, water and alcohol, sand and water

(b) Chalk and sand, water and petrol, iron and sulphur, salt and water

(c) Gold, iron sulphide, milk, water

Give two examples for each of the following types of mixtures.

(a) solid-solid

(b) solid-liquid

(c) liquid-gas

(d) gas-gas

Define the following with an example for each:

(a) Pure substance

(b) Impure substance

(c) Alloy

(d) Solution

(e) Heterogeneous mixture

(f) Homogeneous mixture

Give one difference between pure substances and mixtures.