Explanation

Helium  and Argon is a noble gas, part of Group 18 in the periodic table.

Helium (He)

The lightest noble gas, helium is used in hot air balloons and airships.

It's also used in air containers for deep-sea divers.

Argon (Ar)

Argon makes up 0.93% of the Earth's atmosphere.

It can be prepared by fractional distillation of liquid air.