Final answer:
Noble gases are not radioactive and are monatomic, meaning they exist as single atoms.
Step-by-step explanation:
Noble gases are not radioactive and are monatomic.
Noble gases are a group of elements on the periodic table that include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). These gases are all found in Group 18 of the periodic table and have very stable electron configurations, making them highly unreactive.
Since noble gases have complete outer electron shells, they exist as single atoms (monatomic) and do not form stable compounds with other elements.
Learn more about Noble gases