化学老师都知道，利用几种不相溶混密度又不同的溶剂，分别溶解一些特定的溶质后，把形成的不同颜色的溶液在玻璃容器中混合静置，各种颜色的溶液即能分层，呈彩虹状。下面的实验，使用不同浓度的糖水中，分别滴加红、黄、绿、蓝的实用色素，而后小心地逐一加入一只玻璃杯中，也能使四种颜色的溶液在杯中形成鲜艳的彩虹。

How to Make a Rainbow in a Glass

Today, we are going to make a rainbow. Do you like rainbows? I love rainbows. Well, today we are going to show you how to make a rainbow in a glass.

Materials to Make a Rainbow in a Glass

To make this, you will need: five glasses; sugar; food coloring; a spoon; water, preferably hot .

Dissolve the Sugar in the Glasses

First, we are going to change the density in all of our glass. Line your glasses up, and add one tablespoon of sugar to the first glass, two tablespoons into the second, three tablespoons of sugar into the third glass, and four tablespoons into the fourth glass. Add three tablespoons of water into the four glasses. Keep the fifth glass completely empty.

If your sugar is having a hard time dissolving in the four glasses, add one extra tablespoon into each glass.

Make a Rainbow in a Glass

Next, add two to three drops of red food coloring into the the first glass. Then, add the same amount of yellow into the second glass, green in the third glass, and blue into the fourth glass. Use your spoon to stir each solution.

Now, pour one fourth amount of the blue solution into the fifth glass. Add another fourth of green on top of the blue. To do this, place your spoon down the glass. Rest it slightly above the blue layer, and pour the green solution down the back of the spoon. Doing this will not disturb the blue solution so much. Add another fourth of yellow solution on top of the green layer. And fill the cup the rest of the way up with the red solution.

And there you have it; your rainbow in a glass.