(a) What is meant by (i) elements (ii) compounds, and (iii) mixtures? Write down the names of two elements, two compounds and two mixtures.
(b) Classify the following into elements, compounds and mixtures :
Marble, Air, Gold, Brass, Sand, Diamond, Graphite, Petroleum, Common salt, Sea-water, Chalk
Identify the following as mixture or compound. [2 MARKS] (i) blood (ii) common salt (iii) sugar (iv) brass