| Quantity | Value | Units |
Value | Units |
| Atomic number |
1 |
|
| |
| Atomic mass |
2.014101764(13) |
g mole-1 |
| |
| Specific gravity
(20° C, 1 atm) |
1.677E-04 |
g cm-3 |
| |
| Mean excitation energy |
19.2 |
eV |
| |
| Minimum ionization |
2.053 |
MeV g-1cm2 |
3.444E-04 |
MeV cm-1 |
| Nuclear collision length |
51.3 |
g cm-2 |
3.062E+05
| cm |
| Nuclear interaction length |
71.8 |
g cm-2 |
4.280E+05
| cm |
| Pion collision length |
81.4 |
g cm-2 |
4.855E+05
| cm |
| Pion interaction length |
110.1 |
g cm-2 |
6.567E+05
| cm |
| Radiation length |
125.98
| g cm-2 |
7.512E+05
| cm |
| Critical energy |
345.50 |
MeV (for e-) |
339.03
| MeV (for e+) |
| Molière radius |
7.73 |
g cm-2 |
4.611E+04
| cm |
| Plasma energy ℏωp |
0.26 |
eV |
| |
| Muon critical energy |
1858. |
GeV |
| |
| Boiling point @ 1 atm |
23.65
| K |
-249.5
| C |
| Triple point |
18.69
| K |
-254.5
| C |
| Index of refraction
(0° C, 1 atm, Na D) |
138.
| (n-1)x106 |
|
| |
For muons,