2.58 for each element, give the following information:
[1] total number of electrons; [2] group number; [3] number
of valence electrons; [4] period; [5] number of the valence
shell.
a. oxygen b. sodium c. phosphorus

1. Oxygen

Total no of electrons 8

Group 6

No of valence electrons 6

Period 2

No of valence shell 2

2.Sodium

Total no of electrons 11

Group 1

No of valence electrons 1

Period 3

No of valence shell 3

3. Phosphorus

Total no of electrons 15

Group 5

No of valence electrons 5

Period 3

No of valence shell 3