The table shows the particles in two neutral atoms.
| Atom | Protons | Neutrons | Electrons |
|---|---|---|---|
| P | 6 | 6 | 6 |
| Q | 6 | 8 | 6 |
The relative masses of a proton and a neutron are both 1. Ignore electron mass.
Which gives the difference in relative mass and the difference in total charge between the atoms?
Mass difference 0; charge difference 2
Mass difference 2; charge difference 0
Mass difference 0; charge difference 0
Mass difference 2; charge difference 2