What group of elements from the periodic table is the most stable group because the outer-most layer of their

a. alkali metals

b. halogens

c. noble gases

d. halogens

c - because they have a full outer shell of electrons

c. noble gases

This is Group 0 of the periodic table and is made up of: He, Helium; Ne, Neon; Ar, Argon; Kr, Krypton; Xe, Xenon; Rn, Radon.

They all have a full outer shell of electrons, which is why they are in Group 0, as their outermost shell technically contains no electrons. (although this is sometimes thought of as Group 8, and having a full outer shell)

They are also described as "inert" because they are so unreactive and are nearly always found in their element state, and do not readily form compounds.

(c)

They is so stable, they am inert...(...or "noble"...)