Which of the following best describes the correct Lewis dot structure for the neutral compound AsH3?

• A. Arsenic (As) is surrounded by three hydrogen atoms, each connected by a triple bond, and two lone pairs on As.
• B. Hydrogen atoms are arranged in a linear structure with As in the center and no lone pairs on As.
• C. Arsenic (As) is the central atom with three single bonds to hydrogen atoms and one lone pair on As.
• D. Arsenic (As) is the central atom with three double bonds to hydrogen atoms and no lone pairs on As.

Answer: (C)

Verified step by step guidance

1. Identify the total number of valence electrons for the molecule. Arsenic (As) is in group 15, so it has 5 valence electrons, and each hydrogen (H) has 1 valence electron. For AsH3, total valence electrons = 5 + 3(1) = 8 electrons.
2. Determine the central atom, which is usually the least electronegative element that can form multiple bonds. Here, arsenic (As) is the central atom, and the three hydrogens are terminal atoms.
3. Draw single bonds between the central arsenic atom and each hydrogen atom. Each single bond represents 2 electrons, so 3 bonds use 6 electrons.
4. Distribute the remaining electrons as lone pairs on the central atom. Since 6 electrons are used in bonds, 8 - 6 = 2 electrons remain, which form one lone pair on arsenic.
5. Check the structure for the octet rule. Arsenic has 3 bonds (6 electrons) plus 1 lone pair (2 electrons), totaling 8 electrons, satisfying the octet rule. Hydrogen atoms each have 2 electrons from their single bond, satisfying their duet rule.