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托盘天平在中学化学实验中占有重要位置,以此为目的设计一些选择题来考察学生是否达到应知会用的标准及如何用平衡的观点来看待天平上的化学反应,对于培养学生分析问题和解决问题的能力,具有很高的实用价值。一、物、码位置颠倒对实验数据的影响例1.某学生在天平左盘放15克砝码,在右盘放称量物,将游码移至0.4克处时,天平恰好平衡,则称量物的质量是( )。 (A) 15克 (B) 15.4克 (C) 14.2克 (D) 14.6克 (E) 无法确定
The tray balance occupies an important position in middle school chemistry experiments. With this as its purpose, we design some multiple-choice questions to examine whether students have reached the standard for knowledge and how to use a balanced point of view to view chemical reactions on the balance. The ability to solve problems has a high practical value. First, reverse the influence of the position of the object and the code on the experimental data. Example 1. A student puts a 15 gram weight on the left side of the scale, puts a weighing object on the right side of the scale, and moves the flop to 0.4 gram. The balance is exactly balanced. Weighing mass is (). (A) 15g (B) 15.4g (C) 14.2g (D) 14.6g (E) Unsure