In the molecule $C_2{H}_4$ (ethene), what is the hybridization at each carbon atom?

• A. Each carbon atom is ${\mathrm{sp}}^2$ hybridized.
• B. Each carbon atom is ${\mathrm{sp}}^3$ hybridized.
• C. One carbon is $\mathrm{sp}$ and the other is ${\mathrm{sp}}^2$ hybridized.
• D. Each carbon atom is $\mathrm{sp}$ hybridized.

Answer: (A)

Verified step by step guidance

1. Identify the molecular formula given: C\_2H\_4, which corresponds to ethene, a molecule with a carbon-carbon double bond.
2. Recall that the hybridization of a carbon atom depends on the number of regions of electron density (bonds and lone pairs) around it. In ethene, each carbon forms three sigma bonds: two with hydrogen atoms and one with the other carbon atom.
3. Since each carbon forms three sigma bonds and has no lone pairs, the steric number is 3, which corresponds to sp\^2 hybridization.
4. Understand that the double bond consists of one sigma bond (from sp\^2-sp\^2 overlap) and one pi bond (from unhybridized p orbitals overlapping sideways). This confirms the sp\^2 hybridization for both carbons.
5. Conclude that each carbon atom in ethene is sp\^2 hybridized due to the trigonal planar arrangement of bonds around each carbon.