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本刊1955年4月号赵苏生和丁惋如二位先生所写的“关於初中化学铁和其他金属的教学法”一文,基本上是很好的,现在只把我个人的三点意见提出来以供作者和读者的参考,如果有不正确的地方,还希望大家予以指正。 (一)课文第一节铁的物理性质最后一段“把具有磁性的铁加热;它的磁性就逐渐减弱,热到760℃或更高的温度的时候,磁性就会完全消失,可是冷却以后磁性又会重新出现”。而作者写为“但铁受热后磁性减弱,760℃以上完全失去磁性,冷却后也不能恢复磁性”。很容易引起人认为课本是错了。其实课本上的磁性是指铁磁性,铁都具有铁磁性,除铁外,镍和钴以及稀土金属钆在0℃时也具有铁磁性,他们都能被磁体所吸引。但是铁的
The article “Teaching Methods on Junior High School Chemical Iron and Other Metals”, written by Zhao Susheng and Ding Ssu, in April 1955, is basically very good. Now, only my personal opinion of three points For reference for the author and reader, if there is not the right place, but also hope that everyone correct it. (A) the text of the first section of the physical properties of iron The last paragraph “to the iron with magnetic heating; its magnetic gradually weakened, heat to 760 ℃ or higher temperature, the magnetism will disappear completely, but after cooling magnetism Will reappear. ” The author wrote that “but the magnetic iron weakened after heating, above 760 ℃ completely lost magnetic, cooling can not recover after the magnetic.” It is easy to cause people to think that textbooks are wrong. In fact, the textbook refers to the magnetic ferromagnetism, iron is ferromagnetic, except for iron, nickel and cobalt and rare earth metal gadolinium also have ferromagnetic at 0 ℃, they can be attracted by the magnet. But iron