Why does ammonia () possess a significantly higher dipole moment () compared to nitrogen trifluoride — Chemical Bonding Chemistry Question

💡 Solution & Explanation

Both have pyramidal shapes. In $NH_3$, the $N$ is more electronegative than $H$, so the resultant $N-H$ bond dipole vector points towards $N$, matching the direction of the lone pair orbital dipole, adding up. In $NF_3$, $F$ is more electronegative, so the $N-F$ bond vectors point away from $N$, opposing the lone pair orbital dipole and decreasing the net dipole moment.