Which of the following is **not** a noble gas?

Noble gases (group 18): He, Ne, Ar, Kr, Xe, Rn, Og. All chemically inert in their natural state (Xe and Kr can form a few compounds under extreme conditions). **Bromine** is a halogen (group 17), not a noble gas. It's a reactive non-metal, liquid at room temperature, deep red-brown.