[36~37]

                                                 Water Molecules on the Move
This experiment is great for testing the diffusion of food coloring in hot and cold water.
Pour some water, drop in some food coloring and watch what’s happening.
√ What you'll need:

A clear glass filled with hot water

A clear glass filled with cold water

Food coloring

An eye dropper
√ How to do:
1. Fill the glasses with the same amount of water, one cold and one hot.
2. Put one drop of food coloring into both glasses as quickly as possible. Picture 1
3. Watch what happens to the food coloring.
√ What's happening?
If you watch closely, you will notice the food coloring spread faster throughout the hot water than in the cold. The
molecules in the hot water takes less time to spread the food coloring than those in the cold water.

molecule 分子； experiment 實驗； dropper 滴管； spread 擴散
【題組】36. Look at the picture 1. Which glass is filled with hot water, A or B?
(A) Neither of them is.
(B) Both of them are.
(C) A is.
(D) B is.