Write the chemical formula and name the elements present in the following compound;

Sulphur dioxide.

Classify the following molecules as the molecules of element or compound.

Define the element with an example.

Define the following term with an example;

Compound.

Define the metal with an example.

Define the non-metal with an example.

Define the metalloid with an example.

Write the symbols for the following elements and classify them as solid, liquid and gas.

Aluminium, carbon, chlorine, mercury, hydrogen and helium.