Respuesta :
Answer:
Barium= Group 2, 2 valence electrons
Lead= Group 14, 4 valence electrons
Bismuth= Group 15, 5 valence electrons
Potassium= Group 16, 6 valence electrons
Explanation:
When you move down, from left to right, the groups on the periodic table, the valence electrons increase.
Ex: Hydrogen is in Group 1, so it has 1 valence electron.
Now for the elements with double digits, like 18, then you take the second number.
Ex: Helium is in Group 18, so it has 8 valence electrons.