Period

Shells

Quantity

Of elements

Atomic

numbers

Filling the

levels

I

1s

2

1, 2

2

II

2s

2

3,4

2-2

2p

6

5-10

2-8

III

3 s

2

11,12

2-8-2

3 p

6

13-18

2-8-8

3 d

10

19-28

2-8-18

IV

4 s

2

29-30

2-8-18-2

4 p

6

31-36

2-8-18-8

4d

10

37-46

2-8-18-18

V

5 s

2

47,48

2-8-18-18-2

5 p

6

49-54

2-8-18-18-8

5d

10

55-64

2-8-18-18-18

5f

14

65-78

2-8-18-18-32

VI

6 s

2

79,80

2-8-18-18-32-2

6 p

6

81-86

2-8-18-18-32-8

6d

10

87-96

2-8-18-18-32-18

6f

14

97-110

2-8-18-18-32-32

VII

7 s

2

111-112

2-8-18-18-32-32-2

7 p

6

113-118

2-8-18-18-32-32-8