Final answer:
In acetylene (C₂H₂), the left carbon atom has three bonding pairs (one with a hydrogen atom and two as part of the carbon-carbon triple bond) and zero lone pairs.
Step-by-step explanation:
The student has asked to count the number of binding pairs and the number of lone pairs around the left carbon atom in an acetylene molecule. In the case of acetylene (C₂H₂), each carbon atom forms one sigma (σ) bond with the other carbon atom and two pi (π) bonds. Additionally, each carbon atom forms one sigma bond with a hydrogen atom. Since these are all the electrons available for the carbon atom, there are no lone pairs on either carbon atom in acetylene.
Therefore, around each carbon atom in acetylene there are three bonding pairs (one σ bond with a hydrogen atom and two π bonds as part of the triple bond with the other carbon atom) and zero lone pairs.