What word or two-word phrase best describes the shape of the hydrogen cyanide ( HCN ) molecule?

The hydrogen cyanide (HCN) molecule is best described as "linear." This is due to its molecular structure, where atoms are arranged in a straight line. In HCN, there is a hydrogen (H) atom bonded to a carbon (C) atom, which is then triple-bonded to a nitrogen (N) atom. The linear shape arises from the arrangement of electron domains around the carbon atom, which results in a bond angle of approximately 180 degrees. This configuration is typical for molecules with a triple bond, as it minimizes electron repulsion between the bonded atoms. Thus, the phrase "linear molecular geometry" succinctly captures the spatial arrangement of atoms in the HCN molecule.