I am stuck on a homework question that states:
A piece of solid bismuth is heated strongly in oxygen.
The answer key states the answer as $\ce{Bi + O2 → Bi2O3}$. However, it is to my understanding that the metal Bismuth has a charge of +5 because of its location on the periodic table. Therefore, $\ce{(+5)[charge of Bi]*2 + (-2)[charge of oxygen]*5 = 0}$ giving me $\ce{Bi2O5}$. Please advise.