字母型题的特点是用字母代替数字,结果是用字母表示的表达式,这种题对初中生来说往往就是一种难题,它打破了以往以直观的形象思维思考问题的方式,不但考查了学生的基础知识,又考查了综合分析能力,下面仅对几个比较典型的字母型题加以分析。 例1.某微粒结构示意图为,当x-y=10时,该微粒所带电荷为___。 分析:根据已知x-y=1O,有x=10+y。又根据原子中质子数=核外电子总数,由于该 Letter-type questions are characterized by letters instead of numbers. The result is an expression expressed by letters. This type of question is often a difficult problem for junior high school students. It breaks the way of thinking in the past with intuitive visual thinking, not only examining The basic knowledge of students and the comprehensive analysis ability were examined. Only a few typical letter-type questions were analyzed below. Example 1. A schematic diagram of the structure of a particle is that when x-y=10, the particle has a charge of ___. Analysis: According to the known x-y=1O, there is x=10+y. And according to the number of protons in the atom = the total number of electrons outside the nuclear, due to