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(a) Yes. Rust is iron oxide (Fe₂O₃) which is not same as Iron (Fe). Both are different substance.

(b) No. Rusting of iron is a chemical change resulting in the formation of new substance Iron oxide as product. It can’t be reversed by any simple method.

(c) Yes, rusting of iron is a chemical change. Iron combines with oxygen in presence of water to form a new substance ‘iron oxide’. The iron oxide is rust.

Iron (Fe) + Oxygen (O2, from the air) + water (H2O) —> rust (iron oxide Fe2O3)

It can’t be reversed. Hence, Rusting is a chemical change.

(d) Examples of similar type of chemical change are:

i) Burning of magnesium ribbon to form magnesium oxide.

ii) Souring of milk.