Answer:
Noble Gases
Step-by-step explanation:
For this question, what does one of them have that the others don't?
Alkali Metals - These are in column 1 of the periodic table. They are the ones that have a charge of positive 1 since they give away their 1 electron in order to be stable.
Alkali Earth Metals - These are in column 2 of the periodic table. They are the ones that have a charge of positive 2 since they give away their 2 electrons in order to be stable.
Noble Gases - These are the elements in the last column of the periodic table. These elements do not need to give away or accept electrons because they are complete and stable!
Halogens - These are in column 17 in the periodic table. They are right next to the halogens, but still are not complete as they need 1 more electron in order to be stable. These elements have a charge of -1 because they take away an electron from another element (mainly the alkali metals) in order to be stable.
So, based off of their definitions, the only ones that do not need to gain or lose electrons are the noble gases. This is because they are complete and stable, the only ones out of these that do not need anything.