An element X belongs to group 2 and another element Y belong to group 15 of the periodic table :
(a) What is the number of valence electrons in X ?
(b) What is the valancy of X ?
(c) What is the number of valence electrons in Y ?
(d) What is the valancy of Y ?
(a) Electron X belongs to the group 2nd of the alkali metals so the number of valence electrons in element X is 2.
(b) The valency of the element X is 2.
(c) The element belongs to the 15 group so the number of valence in Y is 5.
(d) Valency of electron Y is 5.