(a) Name two metals which are found in nature mainly in the free state (as metallic elements).
(b) Name two metals which are always found in the combined state.
(c) What iron compound is present in haematite ore? Also, write its chemical formula.
(a) Gold (Au) and silver (Ag) are found in nature in free state. This is because they are non-reactive metals.
(b) Sodium (Na) and magnesium (Mg) are always found in the combined state. This is because they are highly reactive and their oxides are highly stable.
(c) Haematite ore contains iron (III) oxide. Its chemical formula is Fe2O3.