Question

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

Answer 1

(a) All the elements in the same column as boron have the same number of valence electrons (3). So, 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). So, they all have valency equal to 1.