10 Quick Facts about Helium

                This is a diagram of a helium atom, which has 2 protons, 2 neutrons, and 2 electrons.

1. The atomic number of helium is 2, meaning each atom of helium has two protons.
2. Helium has the lowest melting point and boiling point of the elements, so it only exists as a gas except under extreme conditions.
3. Helium is the second-lightest element.
4. Helium is the second-most abundant element in the universe, though it is much less common on Earth.
5. Helium is colorless, odorless, tasteless, non-toxic, and inert.
6. Most helium is obtained by extracting it from natural gas.
7. Helium is the second-least reactive noble gas (after neon).
8. Helium is mono atomic under standard conditions.
9. Inhaling helium temporarily changes the sound of a person's voice. Though helium is non-toxic, breathing it can result in asphyxiation due to oxygen deprivation.
10. Evidence of helium's existence came from observation of a yellow spectral line from the sun.

[Source : About.com]