Question

3. The table on the next page is made on the basis of the modern periodic table. Write in it the
electronic configuration of the first 20 elements below the symbol, and write the valency
(as shown in a separate box).
4. What is the periodic trend in the variation of valency while going from left to right within​

Answer 1

Explanation:

Element symbol Electronic Configuration

Hydrogen H 1

Helium. He 2

Lithium. Li 2,1

Berelium. Be 2,2

Boron. B 2,3

Carbon. C 2,4

Nitrogen. N 2,5

Oxygen. O 2,6

Fluorine. F 2,8

Neon. Ne 2,9

Sodium. Na (Natrium) 2,8,1

Magnesium. Mg 2,8,2

Aluminium. Mg 2,8,3

Silicon. Si 2,8,4

Phosphorus. P 2,8,5

Sulphur. S 2,8,6

Chlorine. Cl 2,8,7

Argon. Ar 2,8,8

Potassium. K (Kelium) 2,8,8,1

Calcium. Ca 2,8,8,2