Respuesta :
Answer:
a. period 6
b. group 2
Explanation:
a.The atoms in the first period have electrons in 1 energy level. The atoms in the second period have electrons in 2 energy levels. The atoms in the third period have electrons in 3 energy levels. The atoms in the fourth period have electrons in 4 energy levels and same goes with 6 energy levels
b. 1 valence electron= group 1
2 v.e = group 2
3 v.e = (3+10) = group 13