Question

(b) What property do all elements in the same column of the Periodic Table as fluorine have in common?

Answer 4:

(a) All the elements in the same column as boron have the same number of valence electrons (3). Hence, they all have valency equal to 3.

(b) All the elements in the same column as fluorine have the same number of valence electrons (7). Hence, they all have valency equal to 1.

Answer 1

For representative elements, the valency of the element is either equal to number of valence electrons( for 1,2,3 and 4 valence electrons) or 8 - number of valence electrons ( for 5,6 and 7 valence electrons).Hence for boron family, the valency is equal to 3 and for halogens the valency is equal to 8-7 = 1