For the neutral molecule NH3, how many bonding groups and lone pairs are present around the central nitrogen atom?

• A. 3 bonding groups and 1 lone pair
• B. 1 bonding group and 3 lone pairs
• C. 2 bonding groups and 2 lone pairs
• D. 4 bonding groups and 0 lone pairs

Answer: (A)

Verified step by step guidance

1. Identify the central atom in the molecule NH3, which is nitrogen (N).
2. Determine the total number of valence electrons for nitrogen. Nitrogen has 5 valence electrons.
3. Recognize that NH3 has three hydrogen atoms bonded to nitrogen, so there are 3 bonding groups (each N-H bond counts as one bonding group).
4. Calculate the remaining valence electrons on nitrogen after forming bonds. Since each bond uses 2 electrons (one from N and one from H), nitrogen uses 3 electrons for bonding, leaving 2 electrons (one lone pair) on nitrogen.
5. Conclude that around the central nitrogen atom, there are 3 bonding groups and 1 lone pair.