He noble gases include helium, neon, argon, krypton, xenon, and radon. what property do these elements share?
a. they readily form compounds with other elements.
b. they were discovered in ancient times.
c. they are never found in the earth's atmosphere.
d. they are normally unreactive with other elements.

Option (d) is the correct answer.

Explanation:

Noble gases are defined as the elements which have completely filled valence orbital.

Elements present in group 18 of the periodic table are all noble gases.

For example, helium is a noble gas and its electronic configuration is .

Since, all the noble gases have completely filled valence orbital. So, they neither need to gain or lose an electron because they are already stable.

Hence, noble gases are normally unreactive in nature.

Thus, we can conclude that property shared by noble gas elements is that they are normally unreactive with other elements.

i'm pretty sure it is letter c.) car