Final answer:
CO is isoelectronic to N2, meaning they have the same number of electrons and electron configuration. CO is polar with dipole-dipole attractions, while N2 is nonpolar with only London forces, resulting in CO having a higher boiling point.
Step-by-step explanation:
When we say that CO is isoelectronic to N2, we mean that carbon monoxide (CO) and nitrogen (N2) have the same number of electrons and, therefore, the same electron configuration. Both molecules have a total of 14 electrons each. Isoelectronic species often share similar physical properties due to the similarities in their electron structure. However, the properties such as boiling point can differ based on their molecular polarity.
CO has a polar bond due to differences in electronegativity between C and O, leading to dipole-dipole attractions. N2, on the other hand, is nonpolar and has only London dispersion forces, which are weaker than the dipole-dipole forces in CO. Therefore, CO has a higher boiling point than N2.