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一题多变,一题多解,有利于培养学生思维的灵活性、敏捷性和批判性,提高学生的发散思维。一道较好的中考题,不仅能使学生加深对概念、定义、定律等基础知识的理解,而且是培养学生发散思维的有效途径.下面就两道中考化学选择题的多种解法提供给同行们商榷。例1在Fe O、Fe2O3、Fe3O4三种化合物中,与等质量铁元素相结合的氧元素的质量比为()。A.6∶8∶9 B.12∶8∶9 C.2∶3∶6 D.1∶3∶41.“最小公倍数”法根据Fe O、Fe2O3、Fe3O4的化学式,可知每个分子中所含铁原子个数依次为1、2、3,则铁原子个数的最小公倍数为6,所以它们的计量数应为6Fe O-3Fe2O3-2Fe3O4,而得氧原子个数比为
Changeable questions, multiple answers, help students develop flexibility in thinking, agility and critical, improve students’ divergent thinking. A better senior high school entrance examination, not only enable students to deepen the understanding of concepts, definitions, laws and other basic knowledge, but also to cultivate students an effective way to divergent thinking.After the two entrance exam chemistry multiple choice questions available to colleagues Discuss. Example 1 In FeO, Fe2O3, Fe3O4 three compounds, with the quality of the iron element is combined with the mass ratio of oxygen (). A.6:8:9 B.12:8:9 C.2:3:6 D.1:3:41. “The least common multiple ” method According to the formula of Fe O, Fe2O3, Fe3O4, we can see that each molecule In which the number of iron atoms in turn 1,2,3, then the least common multiple of the number of iron atoms is 6, so their measurement should be 6Fe O-3Fe2O3-2Fe3O4, and the number of oxygen atoms is