The noble gases are the right-most column of elements on the periodic table, which includes helium, neon, argon, krypton, xenon, and radon.
The noble gases are the most unreactive elements because their outer shell of valence electrons is already full, causing them to not need to bind with other elements to become stable.
- ↑ Fishbaugh K.E. et al. Geology and Habitability of Terrestrial Planets; Springer Science+Business Media; Location unknown. p. 171, (2007)