Noble gases exist as monatomic molecules due to their full electron shell making them stable and nonreactive, therefore they could not bond with other elements making them unable to form compounds.

The Noble Gases have low boiling points that increases as it goes down the group.

Gases have low densities because of their particles are spread apart.

Because of noble gases being nonreactive, argon is used in chip packets to prevent any reaction with the chips, doing so will keep it fresh.

Another notable use is helium which is used in helium balloons.

Neon is used in neon lights (of course ;).