Helium
Atomic number:
2
Atomic weight:
4.002602
Melting point:
-272.2°C @ 26 atmos.
Boiling point:
-268.934°C
Covalent radius:
0.93
Å
Atomic volume:
19.5
cm³/mol
Atomic radius:
0.49
Å
Ionic radius:
--
Å
Electronegativity:
0
Oxidation states:
1st ionization pot.:
24.5874
V
2nd ionization pot.:
54.416
V
3rd ionization pot.:
--
V
Specific heat:
5.193
J/gK
Heat of fusion:
--
kJ/mol
Heat of vapor.:
0.0845
kJ/mol
Thermal conduct.:
0.00152
W/cmK
Electrical conduct.:
--
10^6/cm ohm
Density:
0.0001787
g/cm³
Valence:
0
