Helium | Periodic Table

Atomic Radius (Å)

Helium is a chemical element with symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table. Its boiling and melting points are the lowest among all the elements.

2 Atomic Number

4 u Atomic Mass

null K Melting Point

4.22 K Boiling Point

1.79e-4 g/cm³ Density

0.49 Å Atomic Radius

0.28 Å Covalent Radius

24.59 eV First Ionization Energy

-4.80e+1 Electron Affinity

1 Number of Shells

2 Electron Shell Occupations

5.19 J/g Specific Heat