Quantity | Value | Units | Value | Units | |
Atomic number | 2 | ||||
Atomic mass | 4.002602(2) | g mole-1 | |||
Specific gravity (20° C, 1 atm) | 1.663E-04 | g cm-3 | |||
Mean excitation energy | 41.8 | eV | |||
Minimum ionization | 1.937 | MeV g-1cm2 | 3.222E-04 | MeV cm-1 | |
Nuclear collision length | 51.8 | g cm-2 | 3.117E+05 | cm | |
Nuclear interaction length | 71.0 | g cm-2 | 4.269E+05 | cm | |
Pion collision length | 79.5 | g cm-2 | 4.778E+05 | cm | |
Pion interaction length | 103.6 | g cm-2 | 6.229E+05 | cm | |
Radiation length | 94.32 | g cm-2 | 5.671E+05 | cm | |
Critical energy | 257.13 | MeV (for e-) | 252.23 | MeV (for e+) | |
Molière radius | 7.78 | g cm-2 | 4.677E+04 | cm | |
Plasma energy ℏωp | 0.26 | eV | |||
Muon critical energy | 2352. | GeV | |||
Boiling point @ 1 atm | 4.220 | K | -268.9 | C | |
Index of refraction (0° C, 1 atm, Na D) | 35.0 | (n-1)x106 |