Atomic Number (# of protons)

2

Mass (amu)

4.003

Density

0.179 g/liter (0⁰C, 1 atm)

Electron Configuration

1s²

Oxidation States

Not Available

Atomic Radius (pm)

 Not Available

Ionic Radius (pm)

Not Available

Electronegativity

Not Available

Melting Point (⁰C, 1 atm)

-272

Electron Affinity (eV)

Not Available

Boiling Point(⁰C, 1 atm)

-269

1^st Ionization energy (eV)

24.59

Enthalpy of Fusion (kJ/mole)

Not Available

2^nd Ionization Energy (eV)

Enthalpy of Vaporization (kJ/mole)

0.083

3^rd Ionization Energy (eV)

Specific Heat Capacity ( J/ (g K), 25⁰C, 1 atm)

5.19