3.38 Considering the elements B, Al, Mg, and K, the correct order of their metallic character is :
(a) B > Al > Mg > K
(b) Al > Mg > B > K
(c) Mg > Al > K > B
(d) K > Mg > Al > B
Answer - (d) K > Mg > Al > B
Because the metallic character of an element is the tendency of an element to lose electrons easily. So, moving from left to right across the period metallic character of element decreases.
Here, K and Mg are s-block elements while B and Al belong to p-block elements.
Hence the order is as follows:
K > Mg > Al > B