Question

The metal of group 2 from top to bottom are $Be,Mg,Ca,Sr$ and $Ba.$
(1) Which one of these elements will form ions most readily and why?
(2) State the common feature in the electronic configuration of all these elements.

Answer 1

(1) As we move down the group, the number of shells increases. This results in the increase in the atomic size. As the atomic size increases, the nuclear attraction on the outermost shell decreases and hence the outer electrons are loosely held and hence, ionisation potential decreases. So barium will form ions most readily due to high ionisation potential.

(2) All the atoms in a group have the same number of valence electrons and same valency. All these elements belong to group 2 and hence have 2 valence electrons and also valency is 2.