Question

All of these species have the same number of Valence Electrons as nitrate Ion ,except
(A) Carbonate ion
(B) Bicarbonate ion
(C) NF3
(D) SO3

Answer 1

NO3^-1 has 24 valence electrons.

N has 5 valence electrons, O has 6 but we have 3 of them, so 3x6= 18.

18 + 5 = 23 valence electrons. There is a negative charge on this molecule,

meaning that we have 1 extra electron, so 23+1 = 24 valence electron.

all other species except NF3 have 24 valence electrons, NF3 have 26

N:5*1=5

F:7x3=21

Total=21+5=26

so the answer is the option (c)

SO3

oxygen and sulphur have 6 valence electrons so 3*6+6 =24

Bicarbonate ion

H = 1
C = 4
3 x O = 3 x 6 = 18
Negative charge = 1
================
1 + 4 + 18 + 1 = 24 electrons


Carbonate ion
total of 4 (carbon)+(3x6)(oxygen)+2(negative charge)=24 valence electrons.