CHEMISTRY COMMUNITY

Just for clarification, is the molecule HCN linear because it has a triple bond on the side with a lone pair? Because I though molecules usually slightly bend due to lone pairs.

Yes, HCN is linear. The bent shape only applies to lone pairs on the central atom. The lone pairs on the central atom have a stronger repulsion and thus push the two other bonds slightly closer together.

You can also tell because HCN only has two regions of electron density around the central atom and the shape to position two regions the farthest apart is linear.