| I (eV) | n (electrons/m3) |
| Density ρ (g/m3) | Substances |
| 75 | 3.341 × 1029 | 0.555 | 1,000,000 | Water |
| 74.6 | 3.476 ×1029 | 0.550 | 1,050,000 | Muscle, Skeletal |
| 112 | 5.894 ×1029 | 0.51 | 1,920,000 | Bone, Cortical |