Final answer:
The Lewis dot structure for the ion SCN- (carbon is the central atom) has two lone pairs of electrons.
Step-by-step explanation:
The Lewis dot structure for the ion SCN- (carbon is the central atom) can be represented as follows:
[C&bond;S&triplebond;N]
In this structure, the carbon atom is bonded to both the sulfur (S) atom and the nitrogen (N) atom. Since carbon is the central atom, it does not have any lone pairs of electrons. The sulfur atom has two lone pairs of electrons, and the nitrogen atom also has two lone pairs of electrons. Therefore, the correct answer is option 4: two.