Question 1
How will you find the valency of chlorine, sulphur and magnesium?
(i) Valency of Chlorine :
The electronic configuration of chlorine = 2, 8, 7. It has 7 (more than 4) electrons in its outermost shell. So, the valency of chlorine = 8 – the number of electrons in the outermost shell = 8 - 7 = 1.
Hence, the valency of Cl is 1.
(ii) Valency of Sulphur:
The electronic configuration of Sulphur = 2, 8, 6. It has 6 (more than 4) electrons in its outermost shell. So, the valency of S = 8 – the number of electrons in the outermost shell = 8 - 6 = 2.
Hence, the valency of S is 2.
(iii) Valency of Magnesium:
The electronic configuration of Magnesium = 2, 8, 2. It has 2 (less than 4) electrons in its outermost shell. So, the valency of magnesium = Number of electrons in its outermost shell = 2
Hence, the valency of Mg is 2.