Which one of the following molecules is planar?NF3NCl3PH3BF3

The molecule that is planar among NF3, NCl3, PH3, and BF3 is BF3.

Here's why:

1. NF3 (Nitrogen trifluoride): Nitrogen is the central atom, surrounded by three Fluorine atoms and one lone pair of electrons. This gives it a trigonal pyramidal shape, not planar.

2. NCl3 (Nitrogen trichloride): Similar to NF3, Nitrogen is the central atom, surrounded by three Chlorine atoms and one lone pair of electrons. This also gives it a trigonal pyramidal shape, not planar.

3. PH3 (Phosphorus trihydride): Phosphorus is the central atom, surrounded by three Hydrogen atoms and one lone pair of electrons. This gives it a trigonal pyramidal shape, not planar.

4. BF3 (Boron trifluoride): Boron is the central atom, surrounded by three Fluorine atoms. There are no lone pairs of electrons on the Boron atom, which gives it a trigonal planar shape. Therefore, BF3 is planar.