Determine the number of electron groups for the following cation:AsBr₂⁺.

• A. 2
• B. 3
• C. 4
• D. 1

Answer: (B)

Verified step by step guidance

1. Identify the central atom in the cation AsBr\_2\^+. Here, arsenic (As) is the central atom bonded to two bromine (Br) atoms.
2. Determine the total number of valence electrons for the central atom and the attached atoms. Arsenic (As) has 5 valence electrons, each bromine (Br) has 7 valence electrons, and since the species is a cation with a +1 charge, subtract one electron from the total count.
3. Calculate the total valence electrons: 5 (As) + 2 \times 7 (Br) - 1 (charge) = 18 electrons.
4. Distribute these electrons to form bonds and lone pairs. Each As-Br bond uses 2 electrons, so 2 bonds use 4 electrons. Subtract these from the total to find remaining electrons for lone pairs on As.
5. Count the electron groups around the central atom. Electron groups include bonding pairs and lone pairs. Here, As has 2 bonding pairs (from As-Br bonds) and 1 lone pair, totaling 3 electron groups.