A vessel holds $6.0\ \text{g}$ of helium and $32.0\ \text{g}$ of oxygen, both ideal gases, at the same temperature. Oxygen molecules are rigid and diatomic, and the molar masses are $4\ \text{g/mol}$ and $32\ \text{g/mol}$. What is the ratio of the internal energy of the oxygen to that of the helium?