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Welcome to the Britannica Kids Activities Corner!
欢迎来到大英百科全书儿童活动角！
Today in the Britannica Kids lab, we're going to explore density.
今天，在大英百科全书儿童实验室，我们将探索密度。
Density is what determines whether an object sinks or floats.
密度决定了一个物体是下沉还是漂浮。
Objects that are denser have molecules that are packed more tightly together.
密度越大的物体，分子就越紧密地聚集在一起。
Objects that are less dense have molecules that are more loosely packed.
密度较低的物体具有更松散的分子。
A substance or object will sink in water if it is denser than the water.
如果一种物质或物体的密度比水大，它就会沉入水中。
However -- as we'll see -- you can help an object float by increasing the density of the water.
但是，正如我们将看到的，您可以通过增加水的密度来帮助一个物体漂浮。
Here are the materials you will need: Two glasses, some water, a cup of table salt, a large spoon, and two eggs.
这些是你需要的材料：两个玻璃杯、一些水、一杯食盐、一个大勺子和两个鸡蛋。
First, pour one cup of water into each glass.
首先，在每个杯子里倒入一杯水。
Add five spoonfuls of salt to one of the glasses.
在一个玻璃杯里加五匙盐。
Stir until the salt has dissolved.
搅拌，直到盐溶化。
Now, gently drop an egg into the glass without the salt.
现在，轻轻地把一个鸡蛋放入不加盐的玻璃杯中。
It sinks!
它沉下去了！
But when you gently drop an egg into the glass with the salt, it floats!
但当你轻轻地把一个鸡蛋放进加盐玻璃杯里时，它就会浮起来！
The egg is denser than water, so without any assistance, it sinks.
鸡蛋的密度比水大，所以在没有任何帮助的情况下，它会下沉。
Adding salt to the water makes the water more dense, and allows the egg to float.
向水中加入盐会使水密度变大，并让鸡蛋漂浮起来。
What do you think will happen if you add more plain water to the salt water cup?
如果你在盐水里加更多的白水，你认为会发生什么？
See if you can make some predictions and test them.
看看你是否能做出一些预测，并对其进行检验。
Visit Britannica Kids on the web or contact us on Facebook or Twitter to let us know how your experiment went.
在网上访问大英儿童，或在Facebook或Twitter上联系我们，让我们了解您的实验进展情况。
Stay curious!
保持好奇心！
