What pattern is in a noble gas?

Answer 1

The Atomic Mass increases as you go down the group of Noble Gases.

For example, helium is the first on down the group of Noble Gases. If you have a balloon full of helium, it would rise as it's atomic mass is the lightest of 4.002602 amu. Then, the furthest down the group of noble gases is radon. If you have a balloon full of radon, it would sink down immediately as it's atomic mass is 222.0 amu.

Answer 2

Noble gases have a full outer electron shell, which makes them highly stable and unreactive. This electron configuration is known as the octet rule or the noble gas configuration, and it is a pattern observed in all noble gases.