Answer: raregases

AnswerCrossword Clue
RAREGASES

Krypton and xenon

RAREGASES

Krypton and others

RAREGASES

Helium and neon, e.g.

RAREGASES
They don't react much
RAREGASES
Krypton, xenon, etc.
RAREGASESContents of the rightmost column of a table