Which of the following ions would represent the most common ion of an element from group 2a? a.) a2+ b.) x2- c.) y3+ d.) z+

 The ion  that would  represent  the   most  common  ion  of  an element from   group  2A  is   A 2+

  Group  2A    are   group  of  elements  in periodic table  which   are   known  as alkaline earth  metals.

Example of  group 2A  elements is magnesium  and  calcium.

Group 2A has 2  valence electron  in their outer most  shell  and  therefore  they form ion   which  is  positively charged by  loses  the 2  valence electrons.

for  example  magnesium  (Mg)  which  has  2.8.2    or  [Ne] 3S2 electron configuration  loses  the 2 valence  electron  to  form Mg2+ ion.  Therefore A2+ ion  represent  the common  ion  of  group 2A element.

Explanation:

1. Calculate the molar mass of N₂H₄

2N = 2 × 14 = 28

4H = 2 ×  1  =  4

           Tot. = 32

2. Calculate the mass percent of N