Na, Mg and Al are the elements of the 3"d period of the Modern Periodic Table having group number 1, 2 and 13respectively. Which one of these elements has the (a) highest valency, (b) largest atomic radius, and (c) maximumchemical reactivity ? Justify your answer stating the reason for each.10.

Na, Mg and Al are the elements of the 3"d period of the Modern Periodi

1.	Na, Mg and Al are the elements of the 3"d period of the Modern Periodic Table having group number 1, 2 and 13respectively. Which one of these elements has the (a) highest valency, (b) largest atomic radius, and (c) maximumchemical reactivity ? Justify your answer stating the reason for each.10.
Answer» (a)Highest valency - Al {since valency of Al is 3+ which is more than valencies of Na and Mg which are 1+ and 2+ respectively}(b)Largest atomic radius - Na{since atomic size decreases across a period}(c)Maximum chemical reaction - Na {since reactivity decreases across a period}