Table 1: Fundamental Physical constants.
| Quantities | Symbol, Values (unit) |
| Speed of light | c = 2.99792 × 108 (m/s) |
| reduced Planck constant | ħ = 1.05457 × 10-35 (Js) |
| electron mass | me = 9.10938 × 10-31 (kg) |
| electron charge | -e = 1.60218 × 10-19 (c) |
| electron radius | re = 2.817939 × 10-15 (m) |
| neutron mass | Mn = 1.67262 × 10-27 (kg) |
| neutron charge | 0 (c) |
| neutron radius | rn = 1.11492 × 10-13 (m) |
| proton mass | Mp = 1.672648 × 10-27 (kg) |
| proton charge | +e = 1.60218 × 10-19 (c) |
| proton radius | rp = 1.113386 × 10-15 (m) |
| meson mass | m = 2.305589 × 10-30 (kg) |
| pion π mass | 0.99551904 × 10-28 (kg) |
| pion π massive charge | e' = ± e (c) |
| pion π radius | rm = 1.53472 × 10-18 (m) |
| Cross-section σ unit | 1 barn = 10-28 (m2) |
| Cross-section σ unit | 1 shed = 10-52 (m2) = 10-24 (barn) |