What is the electron geometry around the carbon atom in formaldehyde (CH2O)?

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

Answer: (D)

Verified step by step guidance

1. Identify the central atom in formaldehyde (CH2O), which is the carbon atom.
2. Determine the number of regions of electron density (electron groups) around the carbon atom. These include bonds and lone pairs. In formaldehyde, carbon forms two single bonds with hydrogen atoms and one double bond with oxygen, totaling three regions of electron density.
3. Recall that electron geometry depends on the number of electron groups around the central atom. Three regions of electron density correspond to a trigonal planar electron geometry.
4. Understand that the presence of a double bond counts as one region of electron density, just like a single bond, when determining electron geometry.
5. Conclude that since there are three electron groups around carbon and no lone pairs, the electron geometry is trigonal planar, not tetrahedral, bent, or linear.