Helium (He)

The gas that makes balloons float and voices squeaky.

Helium facts

Symbol
He
Atomic number
2
Atomic mass
4.0026
Family
Noble gases
Period
1
Group
18

What does helium react with?

In our lab helium doesn't make any new substances when it's simply mixed with the others.

Nothing happens when it's simply mixed with 98 of the others. 21 pairings have never been tried, because not enough atoms have ever existed.