Question

.An element X from group 2 of the periodic table reacts with an element Y from group 17 to form a compound
(a). What is the valency of the element X and Y?​

Answer 1

Answer:

(a). What is the valency of the element X and Y?

• since element X is in group 2 it will have only 2 electrons in its valence shell. it can only lose it's electron hence valency of element X is +2

• since element Y is in group 17 it'll have only 7 electrons in it's valence shell

(example: fluorine •atomic no. 9, group 17, electronic configuration = 2,7)

it can gain an electron to complete its shell hence valency of element Y is -1

hope this helps :)