Answer:
8
Explanation:
Ammonium ion [tex](NH_4)^+[/tex] is formed when ammonia [tex](NH_3)[/tex] reacts with hydrogen ion [tex]H^+[/tex]
[tex]NH_3+H^+=NH_4^+[/tex]
In [tex]NH_4^+[/tex] the nitrogen has 5 valence electron and there are 4 hydrogen each has 1 valence electron
So total number of valence electron =4+5=9
But [tex]NH_4^+[/tex] has 1 positive charge on it, it means it losses 1 electron
So total number of valence electron in poly atomic ion of [tex]NH_4^+[/tex] is 9-1=8
