Question

How many valence electrons does the thiocyanate ion, SCN−, have?

a) 16
b) 17
c) 18
d) 19

Answer 1

The thiocyanate ion (SCN-) has a total of 16 valence electrons, which results from summing the individual contributions of sulfur (6), carbon (4), nitrogen (5), and the additional electron from the negative charge (1).

Step-by-step explanation:

To determine the number of valence electrons in the thiocyanate ion (SCN−), we look at the valence electrons contributed by each atom plus the extra electron from the negative charge.

• Sulfur (S) is in group 16 and contributes 6 valence electrons.
• Carbon (C) is in group 14 and contributes 4 valence electrons.
• Nitrogen (N) is in group 15 and contributes 5 valence electrons.
• The extra electron from the negative charge adds 1 more electron.

Adding these together: 6 (S) + 4 (C) + 5 (N) + 1 (additional electron) equals 16 valence electrons in total. Therefore, the correct answer to 'How many valence electrons does the thiocyanate ion, SCN−, have?' is option a) 16.