Conservation of Matter

Conservation of Matter

​Learners can:

• identify the law of conservation of mass

• interpret data to explain the law of conservation of mass

Vocabulary: law of conservation of mass

Curriculum Kit Materials: Science Activity Book (page 9)

Audio Response

What do you think happens to the wood particles when the wood is burning?

Open Audio Recorder

​law of conservation of mass -

states that the amount of matter stays the same, even when matter changes form

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Vocabulary

​Matter changes in many different ways. Even if matter changes states, the amount of matter stays the same. This is called the law of conservation of mass.

​The law of conservation of mass states that the amount of matter stays the same, even when matter changes form. It is also referred to as the law of conservation of matter.

​The same amount of matter exists before and after the green beans are cooked.

The Law of Conservation of Mass states

1. Matter will never vanish or disappear.

2. When matter dissolves, it is just changing form.

3. Matter is conserved, or protected, when it is changing form.

It may seem that matter magically appears or disappears when it changes form, but it just changes from one state to another.

​Water is an example of matter that can exist in all three states: solid, liquid, or gas.

When water changes from a liquid to a solid, it goes through a physical change.

When water freezes, it becomes hard and less dense, but it is still made of the same things.

There are the same number of particles present before and after the change.

​Physical Changes

​Conservation of mass can be demonstrated in several ways. During a physical change, a substance's physical properties may change, but what it is made of does not.

Cutting

​​Mixing

​​Dissolving

​​Changing State

​Physical Changes:

Examples

​With a physical change, you can measure the volume or weight of the item before and after the change. If you measured the volume or weight before and after the change, it would show that the amount of matter did not change.

Although matter forms a new substance during a chemical change, the amount of matter remains the same.

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Chemical Changes

​The volume and the weight of the ash will not be the same as the log before it burned. Still, the law of conservation of mass tells you that no matter was lost. So what happened?

When wood burns, ash falls in many directions. Smoke escapes into the air.

Nothing is contained or controlled.

If you could burn the wood in a sealed container, you could contain all of the matter. The wood and oxygen in the container would create water vapor, other gases, and ashes when burned.

The ashes would not have the same mass as the original piece of wood, but the products have the same mass as the log, water vapor, other gases, and ashes.

No matter is lost. It has just changed.

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Draw

Use this recording sheet along with the Conservation of Mass Interactive

from the lesson. Record the weight of each item in the table.

Wrap Up

You learned that the amount of matter stays the same even when it changes states.

You also explored data to prove that principle.