GENERAL KNOWLEDGE

Detailed explanation-1: -ii) In the second period of the periodic table, the number of valence electrons increases from 1 to 8 on moving from left to right.

Detailed explanation-2: -The number of the valence electrons present in an element is reflected by its position in the periodic table. In a given period number of electrons in a valence shell increases from left to right. Whereas in a group, the number of valence electrons remains the same from top to bottom.

Detailed explanation-3: -As we move from left to right in a periodic table, the valency first increases till 4 and then again decreases to zero.

Detailed explanation-4: -The valency of the elements increases from 1(Na) to 4 (Si) and then decreases to 0 (Ar), on moving from left to right in the third period of the periodic table.

Detailed explanation-5: -On moving from left to right in any period valence electrons keeps on increasing and period gets over when that valence shell gets filled. Even in the first period it has only 2 elements as in that shell only 2 electrons can be fit.