If a molecule has four electron domains around its central atom, the resulting electron domain geometry is:

• A. linear
• B. tetrahedral
• C. trigonal planar
• D. trigonal bipyramidal

Answer: (B)

Verified step by step guidance

1. Identify what is meant by 'electron domains': these are regions of electron density around the central atom, including bonds (single, double, or triple) and lone pairs of electrons.
2. Recall the VSEPR (Valence Shell Electron Pair Repulsion) theory, which predicts the geometry of molecules based on minimizing repulsions between electron domains around the central atom.
3. Know the common electron domain geometries for different numbers of electron domains: for example, 2 domains correspond to linear, 3 to trigonal planar, 4 to tetrahedral, 5 to trigonal bipyramidal, and so on.
4. Since the problem states there are four electron domains around the central atom, match this number to the corresponding electron domain geometry, which is tetrahedral.
5. Understand that this geometry arranges the four electron domains as far apart as possible in three-dimensional space, resulting in bond angles close to 109.5 degrees.