The following Lewis structure depicts the product when boron trifluoride combines with ammonia. How many total valence electrons are shown in this structure
A) 28
B) 30
C) 32
D) 34
E) None of the above

Question

The following Lewis structure depicts the product when boron trifluoride combines with ammonia. How many total valence electrons are shown in this structure 
A) 28 
B) 30 
C) 32 
D) 34 
E) None of the above

Quizplus · Accepted Answer

The Lewis structure shows that there are 8 valence electrons from the three fluorine atoms, 3 valence electrons from the boron atom, and 2 valence electrons from the nitrogen atom.

Total valence electrons = 8 + 3 + 2 = 13

However, since the Lewis structure shows a covalent bond between the boron and nitrogen atoms, we need to subtract 2 electrons for this bond.

Total valence electrons = 13 - 2 = 11

Therefore, the answer is C, with a total of 32 valence electrons shown in the structure.

The Following Lewis Structure Depicts the Product When Boron Trifluoride