Why are burning candles and rusting nails examples of chemical change?

First Rusting is  slow oxidation of iron into iron oxide using H2O and oxygen in atmosphere which is a chemical reaction.

burning is also a oxidation but kinda fast using oxygen in atmosphere to oxidize the hydrocarbon(paraffin wax) in candle to give heat and CO2.

So they are both chemical reactions which happens at different rate.

Outermost (valence) electrons