Question

Na,Mg and Al are the elements of 3rd period of modern periodic table having group no. 1,2 and 13 respectively .which one of these elements has the-(a)highest valency (b)largest atomic radius (c) maximum chemical reactivity . justify your answer stating the reason for each.

Answer 1

longest atomic radius _ Na.
highest valency _ Al.
max react Nair &Mgr r more reactive bcoz they r s-block elements.

Answer 2

al will have the highest valency
mg most reactive