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图像是一种表情达意的载体符号,它如其他信息一样,可以成为一种教学资源。在很多现行教材中,特别注重通过插图采表达一些化学原理、化学现象等知识。在教学中,教师应当引导学生仔细揣摩编者的意图,充分利用插图,去发现插图所传递的化学信息。如,在学习苏教版化学1教材15面图1-10氯化钠在水中的电离时,教师可以引导学生仔细观察图示。学生通过仔细探究发现:①Na~+和CI~-的半径不同;②水分子中氢和氧的半径不同;③Na~+和CI~-周围的水分子数不同;④环绕在Na~+和Cl~-周围的水分子的排列方式不同;⑤物质的溶
An image is an expressive carrier symbol that, like other information, can become a teaching resource. In many current teaching materials, special attention is paid to expressing some chemical principles, chemical phenomena and other knowledge through illustrations. In teaching, teachers should guide students to carefully consider the intent of the editors and make full use of the illustrations to find out the chemical information conveyed by the illustrations. For example, when learning the teach-chemical version of Chemistry 1 in the Soviet version of a textbook, see Figure 1-10. When ionizing sodium chloride in water, the teacher can guide the student to carefully observe the icon. Through careful exploration, the students found that: ①The radius of Na ~ + and CI ~ - is different; ② The radius of hydrogen and oxygen in water molecules is different; ③The water molecules around Na ~ + and CI ~ ~ are different; ~ - around the water molecules arranged in different ways; ⑤ substance dissolved