Exploring the Law of Conservation of Mass

What does the law of conservation of mass state?

• Mass can be created or destroyed in a chemical change.

• Mass decreases during a chemical change.

• Mass remains the same before and after a change.

• Mass increases during a physical change.

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NGSS.MS-PS1-5

Why might the mass appear to change in a lab experiment?

• The scale is faulty.

• Matter changes form.

• Matter disappears.

• New matter is created.

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NGSS.MS-PS1-2

NGSS.MS-PS1-5

In the steel wool burning experiment, what caused the increase in mass?

• Air particles combined with the steel wool.

• Steel wool lost particles.

• Steel wool absorbed water.

• Steel wool expanded.

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NGSS.MS-PS1-2

NGSS.MS-PS1-5

How are air particles represented in the steel wool experiment?

• As red dots.

• As blue dots.

• As gas particles.

• As black dots.

What happens to some of the Alka-Seltzer particles during the reaction with water?

• They dissolve completely.

• They leave the solution as a gas.

• They turn into a solid.

• They remain unchanged.

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NGSS.MS-PS1-2

NGSS.MS-PS1-4

How is water represented in the Alka-Seltzer experiment?

• As red dots.

• As blue dots.

• As gas particles.

• As black dots.

What does the particle diagram help to illustrate?

• The color of the particles.

• The size of the particles.

• The conservation of mass.

• The temperature of the reaction.

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NGSS.MS-PS1-2

NGSS.MS-PS1-5

Why is it important to match the number of particles before and after a change?

• To calculate the volume.

• To measure the temperature.

• To illustrate the conservation of mass.

• To show the change in color.

Tags

NGSS.MS-PS1-5

What can be done to better represent gas particles in a diagram?

• Draw them as solids.

• Remove them from the diagram.

• Make them larger.

• Change their color.

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NGSS.MS-PS3-4

What should you do if your particle diagrams do not match the law of conservation of mass?

• Change the experiment.

• Ignore the differences.

• Adjust the diagrams to communicate the same information.

• Use different colors.

Tags

NGSS.MS-PS1-5