The number of valence electrons in O^2- is :

1. 6
2. 8
3. 10
4. 4

Which of the following is the correct electronic configuration of potassium ?

1. 2, 8, 9
2. 8, 2, 9
3. 2, 8, 8, 1
4. 1, 2, 8, 8

The number of valence electrons in Cl^- ion is:

1. 16
2. 8
3. 17
4. 18

The correct electronic configuration of Fluorine is:

1. 2, 8
2. 8, 2, 1
3. 7, 2
4. 2, 7