Question

can any one tell the
atomicity of 20 elements
plz.....

Answer 1

✍️Hey frnd Here is ur answer‼️‼️

Of the first 20 elements on the periodic table, 15 have more than one isotope which exists naturally on the Earth.
As an aside, it should be noted that no isotope of any element heavier than lead is actually stable and non-radioactive, although their half lives may be extremely long. Bismuth, for example, has just one isotope, which has a half life around a thousand times greater than the age of the Universe.
Hydrogen 2 H-1 and H-2

Helium 2 He-3 and He-4

Lithium 2 Li-6 and Li-7

Beryllium 1 Be-9

Boron 2 B-10 and B-11

Carbon 2 C-12 and C-13

Nitrogen 2 N-14 and N-15

Oxygen 3 O-16, O-17 and O-18

Fluorine 1 F-19

Neon 3 Ne-20, Ne-21 and Ne-22

Sodium 1 Na-23

Magnesium 3 Mg-24, Mg-25 and Mg-26

Aluminium 1 Al-27

Silicon 3 Si-28, Si-29 and Si-30

Phosphorus 1 P-31

Sulphur 3 S-32, S-33 and S-34

Chlorine 2 Cl-35 and Cl-37

Argon 3 Ar-36, Ar-38 and Ar-40

Potassium 2 K-39 and K-41

Calcium 5 Ca-40, 42, 43, 44 and 46.