Which of these do Noble Gases have in common? A All are metals B Same atomic mass C. Same chemical properties D Same atomic number

## Step 1<br />Noble gases are a group of chemical elements with similar properties; they are all odorless, colorless, monatomic gases with very low chemical reactivity. The six naturally occurring noble gases are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn).<br /><br />## Step 2<br />Option A is incorrect because not all noble gases are metals. In fact, none of them are metals.<br /><br />## Step 3<br />Option B is incorrect because noble gases do not have the same atomic mass. Each noble gas has a unique atomic mass.<br /><br />## Step 4<br />Option D is incorrect because noble gases do not have the same atomic number. Each noble gas has a unique atomic number.<br /><br />## Step 5<br />Option C is correct because noble gases do have the same chemical properties. They are all very stable and unreactive due to having a full set of electrons in their outermost energy level.