高中化学新教材中VSEPR模型的b值规定之刍议

新教材关于VSEPR模型中b值的计算,暂未考虑"与中心原子结合的原子"所处的位置环境,即只做了静态规定,是符合新课标要求的;但若拓展运用在CH3COOH这样常见的分子上,会出现与常识不相符的情况,使得VSEPR模型的适用范围受限.从拓展高中化学的教与学的角度出发,笔者认为,将"与中心原子结合的原子"所处的位置环境考虑在...

Discussion on the b Value of VSEPR Model in the New Textbook for Senior High School

In the calculation of b value in VSEPR model in the new textbook,the position environment of“atoms bound to the central atom”is not considered for the time being,that is,only static regulations are made,which is in line with the requirements of the new curriculum standard.However,if it is applied to common molecules such as CH₃COOH,it will be inconsistent with common sense,which will limit the application scope of VSEPR model.From the perspective of expanding the teaching and learning of high school chemistry,the author believes that by taking into account the location of“atoms bonded to the central atom”,namely dynamic accounting of b value,thus expanding the scope of application of VSEPR model.This algorithm does not go beyond the basic theoretical system of high school chemistry and can satisfactorily solve the above-mentioned similar contradictions.The dynamic definition of b value can be specifically described as“b is the maximum number of electrons accepted by the atom bound with the central atom in order to achieve a relatively stable structure”.