Which molecule listed below has a total of 10 valence electrons around the central (first) atom?

Question

Quizplus · Accepted Answer

To determine the total number of valence electrons, add up the valence electrons of each atom and any extra electrons (such as from a negative charge). 
For option A, Xe has 8 valence electrons, each F has 7 valence electrons, and there are 2 extra electrons from the negative charge, giving a total of 24 valence electrons. 
For option B, Se has 6 valence electrons, each Cl has 7 valence electrons, and there are 2 extra electrons from the negative charge, giving a total of 26 valence electrons. 
For option C, Cl has 7 valence electrons, F has 7 valence electrons, and there is 1 extra electron from the negative charge, giving a total of 15 valence electrons. 
For option D, As has 5 valence electrons, each F has 7 valence electrons, and there is 1 extra electron from the negative charge, giving a total of 20 valence electrons. 
Therefore, the only option with a total of 10 valence electrons is option C.

Which Molecule Listed Below Has a Total of 10 Valence