I wanted to ask you in cbse class 12 boards we need to learn atmic masses of all elements given in a book table or 30 to 20 elements.
 

Asked by sukalp | 21st Sep, 2016, 05:35: AM

Expert Answer:

CBSE Class XII Chemistry
 
It is better to know the atomic masses of 30 elements as given below:
 
  

Element

Atomic Number

Atomic Mass

Hydrogen

1

1.0079

Helium

2

4.0026

Lithium

3

6.941

Beryllium

4

9.0122

Boron

5

10.811

Carbon

6

12.0107

Nitrogen

7

14.0067

Oxygen

8

15.9994

Fluorine

9

18.9984

Neon

10

20.1797

Sodium

11

22.9897

Magnesium

12

24.305

Aluminum

13

26.9815

Silicon

14

28.0855

Phosphorus

15

30.9738

Sulfur

16

32.065

Chlorine

17

35.453

Potassium

18

39.0983

Argon

19

39.948

Calcium

20

40.078

Scandium

21

44.9559

Titanium

22

47.867

Vanadium

23

50.9415

Chromium

24

51.9961

Manganese

25

54.938

Iron

26

55.845

Nickel

27

58.6934

Cobalt

28

58.9332

Copper

29

63.546

Zinc

30

65.39

Answered by Prachi Sawant | 21st Sep, 2016, 08:23: PM