Final answer:
The CO molecule has the shortest C—O bond among CO, CO₂, and CH₂O due to its triple bond, which is shorter and stronger than the double bonds in CO₂ and the single bond in CH₂O.
Step-by-step explanation:
In the molecules CO, CO₂, and CH₂O, the C—O bond in CO is the shortest. This is because CO has a triple bond between carbon and oxygen, which is shorter and stronger than single or double bonds. Each type of bond has a characteristic bond length, with triple bonds being the shortest and strongest, followed by double bonds, and then single bonds.
The CO₂ molecule has double bonds, which are shorter than single bonds but longer than triple bonds. In CH₂O, there is a single C—O bond which is longer than both double and triple bonds. Hence, the CO molecule exhibits the shortest C—O bond due to its triple bond nature, and bond lengths decrease with increased bonding between atoms.