Question

answer the questions in the table below about the shape of the ammonia (nh₃) molecule.
how many electron groups are around the central nitrogen atom?
note: one \electron group\ means one lone pair, one single bond,
one double bond, or one triple bond.
what phrase best describes the arrangement of these electron
groups around the central nitrogen atom?
(you may need to use the scrollbar to see all the choices.)

Explanation:

First Question (Number of Electron Groups):

Step1: Analyze NH₃ structure

In \( \text{NH}_3 \), the central N atom forms 3 single bonds with H atoms and has 1 lone pair.

Step2: Count electron groups

Each single bond and lone pair is an electron group. So \( 3 + 1 = 4 \) electron groups.

For \( \text{NH}_3 \), with 4 electron groups (3 bonding, 1 lone pair), the electron - group arrangement (considering both bonding and lone pairs) follows the VSEPR theory. The arrangement that minimizes repulsion for 4 electron groups is tetrahedral. Linear is for 2 electron groups, bent for 3 with 1 lone pair (molecular shape, not electron - group arrangement here), T - shaped for 5 with 2 lone pairs, trigonal planar for 3, trigonal pyramidal is molecular shape, square planar for 6 with 2 lone pairs, square pyramidal for 6 with 1 lone pair, and sawhorse is not a standard electron - group arrangement term. So the electron - group arrangement is tetrahedral.

Answer:

4

Second Question (Electron Group Arrangement):