Question

What happens to a substance if it is oxidized during a chemical reaction?

Answer 1

@aaronq @iGreen @Compassionate

Answer 2

Oxidation involves a loss of electrons.
For instance,\[\color{green}{Zn_{(s)} \rightarrow Zn^{2+}_{(aq)} + 2e^-}\]
Zinc metal has been oxidized, since it has lost two electrons to form a zinc ion.