本题目来源于试卷: Models of Bonding & Structure B.2 The Covalent Model，类别为 IB化学
[单选题]
The electron configuration of carbon is 1${S^2}2{S^2}2{p^2}$ . Why is hybridization helpful for explaining the bonding of carbon in ethene ($C_2H_4$)?[size=1.21em]
A. Hybridization allows the paired 2s electrons to participate in separate σ bonds
B. Hybridization allows the paired 2s electrons to participate in separate π bonds
C. Hybridization allows the paired 2p electrons to participate in separate σ bonds
D. Hybridization allows the paired 2p electrons to participate in separate π bonds
参考答案: A
本题详细解析:
Each carbon atom in ethene forms three σ bonds and one π bond. The s electrons are originally paired but are conceptually unpaired during the formation of the three $sp^2$ orbitals, allowing the σ bonds to form. The p electrons are unpaired in the original atomic orbitals and remain unpaired in the hybrid orbitals. One p orbital in each carbon atom is used to produce the π bond.
This question is moderately difficult as the student must recall the concept of electron unpairing/promotion in hybridization and differentiate between σ and π orbitals without the aid of a diagram.
| 
