Question

Arrangement of electrons in the shells of an atom of first 20 elements

Answer 1

Hydrogen H 1 - - -

Helium He 2 - - -

Lithium Li 2 1 - -

Beryllium Be 2 2 - -

Boron B 2 3 - -

Carbon C 2 4 - -

Nitrogen N 2 5 - -

Oxygen O 2 6 - -

Fluorine F 2 7 - -

Neon Ne 2 8 - -

Sodium Na 2 8 1 -

Magnesium Mg 2 8 2 -

Aluminium Al 2 8 3 -

Silicon Si 2 8 4 -

Phosphorus P 2 8 5 -

Sulfur S 2 8 6 -

Chlorine Cl 2 8 7 -

Argon Ar 2 8 8 -

Potassium K 2 8 8 1

Calcium Ca 2 8 8 2