Classify the following into metals, non-metals and metalloids:

Silicon, Mercury, Diamond, Sulphur, Iodine, Germanium, Sodium, Carbon, Magnesium, Copper, Boron, Helium

Classify the following into elements, compounds and mixtures:

Marble, Air, Gold, Brass, Sand, Diamond, Graphite, Petroleum, Common salt, Sea-water, chalk

What are (i) metals (ii) non-metals, and (iii) metalloids? Give two examples each of metals, non-metals and metalloids.

What is a mixture? Give two example of mixtures.

What is meant by (i) homogeneous mixtures, and (ii) heterogeneous mixtures? Give two examples of homogeneous mixtures and two of heterogeneous mixtures.