十万个为什么·科学启蒙30篇（3）

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为什么磁铁能吸铁

Magnets attract iron because iron atoms have unpaired electrons that create tiny magnetic fields.
In unmagnetized iron, these atomic magnets point in random directions, canceling each other out.
When a strong magnet comes near, it causes many of these tiny fields to line up temporarily.
This alignment turns the iron into a temporary magnet with opposite polarity facing the original one.
Opposite magnetic poles attract, so the iron jumps toward the magnet with noticeable force.
Other metals like nickel and cobalt behave similarly, but aluminum or copper do not react this way.
Heating or dropping a magnetized piece of iron scrambles the alignment and removes its magnetism.
Permanent magnets stay magnetic because their atomic fields lock into place within a rigid crystal structure.
Earth itself acts like a giant magnet, which is why compass needles always point north.
This force works without contact because magnetic fields extend invisibly through space around the magnet.

听 → 读 → 学表达 → 懂 → 今天会说这一句 → 跟读录音 → 自己说一句。

Magnets attract iron because iron atoms have unpaired electrons that create tiny magnetic fields. 磁铁能吸引铁，是因为铁原子含有未配对电子，能产生微小磁场。
In unmagnetized iron, these atomic magnets point in random directions, canceling each other out. 未磁化的铁中，这些原子磁体方向杂乱，相互抵消。
Opposite magnetic poles attract, so the iron jumps toward the magnet with noticeable force. 异名磁极相吸，因此铁会明显受力跃向磁铁。

这篇中文题目最接近哪一句？为什么磁铁能吸铁一次学校运动会的通知一份超市购物清单

课文第一句的意思更接近？磁铁能吸引铁，是因为铁原子含有未配对电子，能产生微小磁场。今天学校放假了。请把窗户打开。

这一课主要在讲什么？（看英文标题） Why Can Magnets Attract Iron? How to cook noodles A maths worksheet

Magnets attract iron because iron atoms have unpaired electrons that create tiny magnetic fields.

Magnets attract iron because iron atoms have unpaired electrons that create tiny magnetic fields.

第一版：录下来、回听、再听标准音。系统打分以后再加。

用今天的表达，自己说一句。

例子：Magnets attract iron because iron atoms have unpaired electrons that create tiny magnetic fields.