Question

rank the elements or compounds in the table below in decreasing order of their boiling points. that is, choose 1 next to the substance with the highest boiling point, choose 2 next to the substance with the next highest boiling point, and so on.
substance chemical symbol, chemical formula or lewis structure
a no
b n₂
c h - c - n - h
h h
:o:
d h - c - c - h
h h
:o:
h h
boiling point select < select < select < select <

Explanation:

Step1: Analyze intermolecular forces

Boiling - point is related to the strength of intermolecular forces. $NO$ is a polar molecule with dipole - dipole forces. $N_2$ is non - polar with only London dispersion forces. Molecules C and D have more complex structures with potential for hydrogen bonding and larger surface areas for London dispersion forces.

Step2: Compare intermolecular forces strength

Hydrogen bonding and larger molecular size generally lead to stronger intermolecular forces. Molecules with hydrogen bonding are likely to have higher boiling points than those with only dipole - dipole or London dispersion forces. Among the given substances, assuming molecules C and D have hydrogen - bonding capabilities and larger molecular weights compared to $NO$ and $N_2$.

Step3: Rank boiling points

The ranking from highest to lowest boiling point: D, C, B ($NO$), A ($N_2$).

Answer:

D, C, B, A