Which of the following statements correctly describes the Lewis dot structure of the ammonium ion (NH_4^+)?

• A. Nitrogen is bonded to four hydrogen atoms and has one lone pair, with a negative charge.
• B. Nitrogen is bonded to two hydrogen atoms and has two lone pairs, with a positive charge.
• C. Nitrogen is surrounded by four single bonds to hydrogen atoms, and the structure carries a positive charge.
• D. Nitrogen is bonded to three hydrogen atoms and has one lone pair, with no overall charge.

Answer: (C)

Verified step by step guidance

1. Recall that the ammonium ion (NH_4^+) consists of one nitrogen atom bonded to four hydrogen atoms and carries an overall positive charge.
2. Draw the nitrogen atom in the center and connect it to four hydrogen atoms using single bonds, since nitrogen typically forms three bonds but can expand its bonding in ions like NH_4^+.
3. Check the number of valence electrons: nitrogen has 5 valence electrons, each hydrogen has 1, so total neutral NH_4 would have 8 electrons. Since the ion has a +1 charge, remove one electron, resulting in 7 electrons to distribute.
4. Assign bonding electrons to the four N-H bonds (each bond has 2 electrons), which accounts for 8 electrons, but since we removed one electron due to the positive charge, the nitrogen has no lone pairs left.
5. Conclude that the correct Lewis structure shows nitrogen bonded to four hydrogens with single bonds, no lone pairs on nitrogen, and the entire ion carries a positive charge.