two elements with symbol X (atomic no. 11) &Y (atomic no. 13) are placed in the III period of the modern periodic table-
a) calculate the valency of each element.
As the elements are of 3rd period, then valance electrons will be in third shell.
For X => electronic configuration is 2,8,1 Hence, Valency = 1
For Y => electronic configuration is 2,8,3 Hence, Valency = 3