CBSE Class 9 Answered

Element

Atomic Number

Atomic Mass

Valency

Hydrogen

1

1.0079

(-1), +1

Helium

2

4.0026

0

Lithium

3

6.941

+1

Beryllium

4

9.0122

+2

Boron

5

10.811

-3, +3

Carbon

6

12.0107

(+2), +4

Nitrogen

7

14.0067

-3, -2, -1, (+1), +2, +3, +4, +5

Oxygen

8

15.9994

-2

Fluorine

9

18.9984

-1, (+1)

Neon

10

20.1797

0

Sodium

11

22.9897

+1

Magnesium

12

24.305

+2

Aluminum

13

26.9815

+3

Silicon

14

28.0855

-4, (+2), +4

Phosphorus

15

30.9738

-3, +1, +3, +5

Sulfur

16

32.065

-2, +2, +4, +6

Chlorine

17

35.453

-1, +1, (+2), +3, (+4), +5, +7

Argon

18

39.0983

0

Potassium

19

39.948

+1

Calcium

20

40.078

+2

Scandium

21

44.9559

+3

Titanium

22

47.867

+2, +3, +4

Vanadium

23

50.9415

+2, +3, +4, +5

Chromium

24

51.9961

+2, +3, +6

Manganese

25

54.938

+2, (+3), +4, (+6), +7

Iron

26

55.845

+2, +3, (+4), (+6)

Nickel

27

58.6934

+2, +3, (+4)

Cobalt

28

58.9332

(+1), +2, (+3), (+4)

Copper

29

63.546

+1, +2, (+3)

Zinc

30

65.39

+2