You cannot create something from nothing and similarly you cannot create less from more, if you didn't balance an equation that needs to be balanced, your product might end up equalling more or less than the total mass of the two elements combined. Which is impossible
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.
This is what i have found i hope this helps
