ALevel化学​17个必备定义

　　ALevel化学考试中比较难理解的就是反应机理（Mechanism），对于想要提升考试成绩的人来说，想要充分掌握和理解反应机理，一些必要的词汇和定义是必须要掌握的，今天小编就为大家总结17个必备定义！

　　Functional group

　　a group of atoms responsible for the characteristic reactions of an organic compound.

　　Homolytic fission

　　the splitting of a covalent bond where each atom retains one electron from the bonding pair.

　　Heterolytic fission

　　the splitting of a covalent bond where one atom retains both electrons from the bonding pair.

　　Free radical

　　an uncharged molecule with an unpaired electron.

　　Initiation

　　an initial chemical reaction which triggers further reactions.

　　Propagation

　　a secondary reaction where there is no net gain or loss of free radicals.

　　Termination

　　the final step in a chain reaction where a reactive intermediate is rendered inactive.

　　Nucleophile

　　a molecule or substance that donates electrons.

　　Electrophile

　　a molecule or substance that acts as an electron pair acceptor.

　　Addition

　　a reaction where two or more molecules react to form a larger molecule.

　　Substitution

　　a reaction where an atom or group is replaced by another atom or group.

　　Elimination

　　a reaction in which two substituents are removed from a molecule in a mechanism with one or two steps.

　　Hydrolysis

　　the splitting up of a compound or molecule using water.

　　Hydrolysis

　　the splitting up of a compound or molecule using water.

　　Condensation

　　the formation of a compound with the release of water.

　　Oxidation

　　the formation of a compound with the release of water.

　　Reduction

　　gain of electrons.

　　关于A-Level化学反应机理的17个定义就为大家推荐到这里了，希望大家能够好好复习，提高备考能力，并且小编建议大家要好好积累词汇，这样才能顺利通过考试，如果还想了解更多关于ALevel学习资料、ALevel官方报名网的信息，可以在线咨询我们或添加客服微信kewo11！