# If a piece of metal, such as calcium or magnesium, reacts with atmospheric oxygen, would you expect the product to have a greater or lesser mass that the reacting metal? Why?

Nov 9, 2016

Should you not tell us this?

#### Explanation:

A metal is oxidized; i.e. it combines with atmospheric oxygen:

$\text{Metal + dioxygen " rarr " Metal oxide}$.

And certainly mass is conserved in every chemical reaction.

If mass is conserved, what should be the mass of the oxide with respect to the starting metal?