Hydrogen and deuterium may be shown by the nuclide symbols $^1_1\text{H}$ and $^2_1\text{H}$ respectively. State one difference between hydrogen and deuterium.
- AThe deuterium atom has twice the number of electrons as the hydrogen atom.
- BThe deuterium nucleus has a charge, but the hydrogen nucleus has no charge.
- CThe deuterium nucleus has less mass than the hydrogen nucleus.
- DThe deuterium nucleus has half the charge per unit mass of the hydrogen nucleus.