试题与答案

课外活动小组的同学从某工厂收集到一些混有少量铁片的细小铜片.为了除去铜片中铁片,

题型:填空题

题目:

课外活动小组的同学从某工厂收集到一些混有少量铁片的细小铜片.为了除去铜片中铁片,活动小组的同学经过讨论,确定了如下方案,请回答有关问题:

(1)方案一:用磁铁吸引铁片.该方法属于______(填“物理”或“化学”)方法.

(2)方案二:用硫酸铜溶液.该方案所利用的原理是利用铁的金属活动性比铜______

(选填“强”或“弱”),该反应化学方程式为______.

(3)你认为还可用______来除去铁片.

(4)上述三种方案中,你认为方案______的操作最简单.

答案:

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答案:B题目分析:中位数是一组数据从小到大(或从大到小)排列后,最中间的那个数(最中间两个数的平均数)。因此这组数据的中位数是第3,4个数的平均数:。平均数是指在一组数据中所有数据之和再除以数据的个数...

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