There are four fundamental interactions, as summarised below:
| Interaction | Associated Charge | Mediating Particle | Relative Strength | Range(m) |
|---|---|---|---|---|
| Gravitation | Mass | Graviton | 1 | infinite |
| Electromagnetism | Electric | Photon | 10 36 | infinite |
| Weak Nuclear Force | Flavour | W & Z bosons | 10 25 | 10 -18 |
| Strong Nuclear Force | Colour | Gluon | 10 38 | 10 -15 |
Note: The electromagnetic and weak nuclear forces have been unified.