What is the electron geometry for a molecule with two regions of high electron density (rheds) surrounding the central atom?

• A. Bent
• B. Tetrahedral
• C. Trigonal planar
• D. Linear

Answer: (D)

Verified step by step guidance

1. Identify what "regions of high electron density" (RHEds) mean: these are areas around the central atom where electrons are likely to be found, including both bonding pairs (shared electrons in bonds) and lone pairs (non-bonding electrons).
2. Recall that the electron geometry describes the spatial arrangement of all electron regions (bonding and lone pairs) around the central atom, not just the atoms themselves.
3. Use the VSEPR (Valence Shell Electron Pair Repulsion) theory, which states that electron regions repel each other and arrange themselves as far apart as possible to minimize repulsion.
4. For two regions of high electron density, the electron pairs will position themselves 180 degrees apart, resulting in a linear electron geometry.
5. Note that the molecular geometry might differ if lone pairs are present, but since the question asks for electron geometry with two RHEds, the correct geometry is linear.