Which of the following species is correctly represented by a valid Lewis dot structure for a neutral compound?

• A. NH3
• B. H2O2 with each oxygen having only one lone pair
• C. NaCl (as Na and Cl atoms, not ions)
• D. CO2 with a single bond between C and each O

Answer: (A)

Verified step by step guidance

1. Recall that a valid Lewis dot structure for a neutral compound must satisfy the octet rule (or duet for hydrogen) for each atom, and the total number of valence electrons must be correctly represented.
2. Analyze NH3 (ammonia): Nitrogen has 5 valence electrons and forms three single bonds with hydrogen atoms (each contributing 1 electron), and it has one lone pair. This satisfies the octet rule for nitrogen and duet for hydrogen, making NH3 a valid Lewis structure.
3. Examine H2O2 (hydrogen peroxide) with each oxygen having only one lone pair: Oxygen typically has two lone pairs in peroxides to satisfy the octet rule. Having only one lone pair on each oxygen means the octet is incomplete, so this is not a valid Lewis structure.
4. Consider NaCl as neutral atoms (Na and Cl atoms, not ions): Sodium (Na) and chlorine (Cl) do not form a stable neutral molecule by sharing electrons; Na tends to lose one electron to become Na⁺, and Cl gains one to become Cl⁻. Therefore, representing NaCl as neutral atoms bonded together is incorrect.
5. Look at CO2 with single bonds between carbon and each oxygen: Carbon needs to form double bonds with oxygen to satisfy the octet rule. Single bonds would leave carbon electron-deficient, so this is not a valid Lewis structure.