| Quantity | Value | Units |
Value | Units |
| Atomic number |
18 |
|
| |
| Atomic mass |
39.948(1) |
g mole-1 |
| |
| Specific gravity
(20° C, 1 atm) |
1.662E-03 |
g cm-3 |
| |
| Mean excitation energy |
188.0 |
eV |
| |
| Minimum ionization |
1.519 |
MeV g-1cm2 |
2.525E-03 |
MeV cm-1 |
| Nuclear collision length |
75.7 |
g cm-2 |
4.557E+04
| cm |
| Nuclear interaction length |
119.7 |
g cm-2 |
7.204E+04
| cm |
| Pion collision length |
101.3 |
g cm-2 |
6.097E+04
| cm |
| Pion interaction length |
149.0 |
g cm-2 |
8.964E+04
| cm |
| Radiation length |
19.55
| g cm-2 |
1.176E+04
| cm |
| Critical energy |
38.03 |
MeV (for e-) |
37.06
| MeV (for e+) |
| Molière radius |
10.90 |
g cm-2 |
6559.
| cm |
| Plasma energy ℏωp |
0.79 |
eV |
| |
| Muon critical energy |
572. |
GeV |
| |
| Melting point |
83.81 |
K |
-189.3
| C |
| Boiling point @ 1 atm |
87.26
| K |
-185.9
| C |
| Index of refraction
(0° C, 1 atm, Na D) |
281.
| (n-1)x106 |
|
| |
For muons,