Arrange the following elements in the increasing order of their metallic character: Mg, Ca, K, Ge, Ga
                
                  Group No             :           1          2                                  13 14
3rd Period            :                       Mg                             
4th Period            :           K          Ca                               Ga Ge
When we move from left to right in a period the metallic nature decreases and all the nonmetals are present in p-block.
On the other hand, when me move from top to bottom in a group the metallic character increases. So,
taking all these trends into consideration:
GeGa
Mg
Ca
K