Question

Tell the Atomic Number and Atomic mass of First twenty elements.
Can share a chart also.​

Answer 1

Answer:

Atomic number Name chemical element Symbol

18                                            Argon                      Ar

19                                        Potassium                      K

20                                          Calcium                      Ca

21                                          Scandium               Sc

Answer 2

Explanation:

ATOMIC NUMBER ELEMENT ATOMIC MASS

1 Hydrogen 1.008

2 Helium 4.0026

3 Lithium. 6.94

4 Beryllium 9.0122

5 Boron 10.81

6 Carbon 12.011

7 Nitrogen 14.007

8 Oxygen 15.999

9 Fluorine 18.998

10 Neon 20.180

11 Sodium 22.990

12 Magnesium 24.305

13 Aluminium 26.982

14 Silicon 28.085

15 Phosphorus 30.974

16 Sulphur 32.06

17 Chlorine 35.45

18 Argon 39.948

19 Potassium 39.098

20 Calcium 40.078