Answer:
2, 8 7 7 valence electrons Group 7
2, 8 , 1 1 valence electrons Group 1
2 8 3 3 valence electrons Group 3
2 4 4 valence electrons Group 4
2 8 8 2 2 valence electrons Group 2
Explanation:
The valency of an electronic configuration of an atom can be used to determine the group an element belongs.
The valency is the number of outermost shell electrons an atom contains.
So;
2, 8 7 7 valence electrons Group 7
2, 8 , 1 1 valence electrons Group 1
2 8 3 3 valence electrons Group 3
2 4 4 valence electrons Group 4
2 8 8 2 2 valence electrons Group 2
