first 20 elements of periodic table

Asked by ashwanishuklafbd | 3rd Jul, 2017, 09:12: PM

Expert Answer:

 
First 20 elements of periodic table are:
 
 

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

Answered by Prachi Sawant | 4th Jul, 2017, 09:40: AM