 Wysłany: Pią 4:17, 01 Kwi 2011 Temat postu: Chemistry Teaching in the classroom questioning te |
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| Chemistry Teaching in the classroom questioning techniques
Unable to adapt, especially the strong continuity of knowledge, and sometimes seems impossible to start, or even too lazy to hands-on, brains. Therefore, the process of teaching and adopting necessary to reverse thinking questions, such analysis can help students improve problem-solving abilities, but also to teach students a learning method, technique. For example, the author talking about issues related to the calculation of chemical formula, the cited example of such a: To determine the content of calcium carbonate in a limestone, limestone samples are weighed 12.5g, add appropriate amount of hydrochloric acid, just to fully reflect, build 4. 4g of carbon dioxide, find the mass of calcium carbonate in limestone. As the title only in the equation can not directly calculate the result, students feel at a loss, no start, so I divided the following steps to questions: First, how to count the mass fraction of calcium carbonate? Second, the first question asked only to know which a volume? Third, how the amount of demand. Such questions, students naturally to answer. I immediately told the students to reverse the thought process is we do question the whole process of the road, the students thought the transition quickly from forward to reverse. 4-level heuristics such questions are asked of people from shallow depth, level and gradient of the questions. [2] have such a problem: a sample of ammonium sulfate (nitrogen 20%), inclusion of ammonium sulfate, urea, ammonium nitrate and other impurities in which. This is a mixed-material element in the calculation of the percentage content of difficult to understand the kinds of questions, if the students do it themselves, more difficult, is not straightforward to explain, but it must enable students to master the problem-solving skills. The author thought that question: First, human urine contains urea, 2% if it contains urea, the nitrogen in human urine what is? Through the analysis of less than 2% of students come to the conclusion. Second, by ammonium sulfate (nitrogen 21.2%) and urea (nitrogen 46.7%) composed of a mixture of nitrogen rate and how much? By thinking about the students concluded: nitrogen was higher than 21.2 % less than 46.7%. Third, make the results of 20%, is another nitrogen rate can only be higher or lower than 20%? Students quickly replied: must be less than 20%, only ammonium nitrate nitrogen by calculating the rate of less than 20%. In short, the classroom teaching in question is one of the means necessary,p90x workout calendar, timely and reasonable questions, both to urge teachers to think and continue to explore ways of new questions, but also inspire and guide students to improve thinking, learning skills to master, will be the the process of teaching brings unexpected results. Therefore, we must rise to the majority of teachers are highly valued. |
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