What weighs more, a nail or a rusted nail ?

1 Answer
May 9, 2016

A rusted nail - assuming no bits of rust have dropped off of it.


Rust is formed when iron is oxidised, typically in the presence of water, resulting in hydrated oxides. All of the atoms of iron are still there, just in combination with oxygen and hydrogen. So the mass of the nail increases by the weight of oxygen and hydrogen that reacts with it.