Heat energy can make many things move or change. When an object is warm or hot, the tiny molecules like to move around and expand. When an object is cool or cold, the tiny molecules like to stay in one place or get close together. Take for example a thermometer. When the liquid inside gets hot or warm from the object being measured, it expands. The only place for the liquid to expand is up the tube. So what do you think happens to a thermometer when the liquid inside get cool or cold? Yep…it contracts or gets closer together. Thus making the liquid go down.
As the 3rd graders are learning how heat energy makes objects change or move, they explored this concept of expanding and contracting by observing what happens to a tea bag in cold and hot water. What do you think happened? See what they observed.
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- Cold Water
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- Hot Water
