Question

what is meant by valency and give valencies of ammonium ,bismuth, barium and hypochlorite

Answer 1

Valency is the number of electrons in the outer shell of an atom.
valency of ammonium : 1
valency of bismuth : 5
valency of barium : 2

Answer 2

Valency is the measure of combining power of an element.It is counted by the no.of electrons in the outer most shell.Shells are named as K,L,M,N,O.......and so on.
atomic no. of bismuth is 83
so,2,8,18,32,18,5.
therefore valency of Bismuth is 5.
Likewise valency of Barium 2
Ammonia as it is a neutral molecule it combines with HCl gives Ammonium chloride,ammonia accepts an hydrogen ion from HCl and forms ammonium ion
which has +1 valency.
Valency of hypochlorite is -1.
Mark it bst plz.