Question

why are the noble gases the least reactive elements

they have an empty inner electron shell

they have a full valence electron shell

they are the most electronegative elements

they are the elements with the smallest atomic mass

Answers

GPT-4o mini
The noble gases are the least reactive elements primarily because **they have a full valence electron shell**. This means that their outermost electron shell is complete, typically holding eight electrons (with the exception of helium, which has two). As a result, they have little tendency to gain, lose, or share electrons, making them very stable and unreactive under normal conditions.

The other options do not accurately explain their low reactivity:
- They do not have empty inner electron shells; rather, their inner shells are filled, which allows their outer shells to be stable.
- They are not the most electronegative elements; that distinction belongs to other elements like fluorine and oxygen.
- Having the smallest atomic mass does not correlate with reactivity trends; elements with low mass can be quite reactive (like lithium or beryllium).

Thus, the correct answer is that noble gases have a full valence electron shell.