Final answer:
The structure of formaldehyde (CH2O) features a carbon atom double-bonded to an oxygen atom with two lone pairs, and two hydrogen atoms single-bonded to the carbon, resulting in a trigonal planar molecular geometry with bond angles around 120°.
Step-by-step explanation:
Formaldehyde, with the chemical formula CH2O, is a simple aldehyde commonly used as an embalming agent and preservative. In its Lewis structure, the carbon atom is double-bonded to the oxygen, which also has two lone pairs of electrons, creating a region of high electron density. This double bond contributes to the molecule's trigonal planar geometry, with bond angles close to 120°. Each of the two hydrogen atoms is single-bonded to the carbon atom, completing the tetrahedral geometry around the carbon atom. The molecular structure is depicted as:
:O:
H-C-H
The oxygen atom has two lone pairs of electrons, and there are three regions of bonding around the carbon atom, which has no lone pairs, providing an acceptable Lewis electron structure for formaldehyde.