Question

Two elements X and Y belong to group 1 and 2 respectively in the same period of periodic table. Compare them with respect to:

(i) the number of valence electrons in their atoms

(ii) their valencies

(iii) metallic character

(iv) the sizes of their atoms

(v) the formulae of their oxides

(vi) the formulae of their chlorides

Answer 1

(i) The number of valence electrons in element X is 1 while in element Y is 2.

(ii) The valency of element X is 1 and that of element Y is 2.

(iii) Element X is more metallic than element Y.

(iv) The size of atom X is more than that of atom Y.

(v) The formula of oxide of element X is X₂O and that of element Y is YO.

(vi) The formula of chloride of element X is XCl and that of element Y is YCl₂.