The following table shows the positions of six elements A, B, C, D, E and F in the modern periodic table

(i) Which element will form only covalent compounds ?
(ii) Which element is a metal with valency two ?
(iii) Out of D and E, which one has a bigger atomic radius ? Give reason for your answers.

Explanation

(i) The element 'E' belonging to group 14 has four valence electrons. It will form only covalent compounds.
(ii) The element 'D ' present in group 2 has two valence electrons. It is a metal with valency 2.
(iii) The elements 'D' and 'E' belong to the same period. Since atomic size decreases along a period, the element 'D ' has bigger atomic radius.