Answer:
3,4,5,6,7,8
Step-by-step explanation:
Groups 13 - 18 are the main group on the periodic table
The group number corresponds the number of valence electrons they contains.
Valence electrons are the number of electrons in the outermost shell of an atom.
So group 13 - 18 corresponds to a valency of 3,4,5,6,7,8.
Groups with a valency of 8 are the noble gases.