Why does this picture demonstrate the Law of Conservation of Mass?

• the number of atoms of each element are the same on both sides

• they start out separate and end up combined

• the same elements are used

• it doesn't demonstrate the Law of Conservation of Mass

Law of conservation of mass states that 

• matter is created
• matter is destroyed
• matter is neither created nor destroyed
• matter does not change

At the end of chemical reactions, what is the total mass of the reactants compared to the total mass of the products?

• the product is doubled
• the product is half the mass of the reactants
• the mass is the same
• the mass changes depending on the reaction

If reaction starts with 20g of reactants it should produce... 

• a total of 40g of product
• a total of 10g of product
• a total of 80 g of product
• a total of 20g of product

Maria fills a bowl with 200 g of water. She puts the bowl of water in the freezer, and the water freezes. Which will most likely be the mass of the frozen water?

• 50 g
• 100 g
• 200 g
• 400 g

The diagram shows water particles in three different phases.

On a summer day, water particles from the ocean change phase as they move into the air. Which of the following models best shows this process?

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Which picture BEST shows what change occurs when heat is added to ice?

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Veronica weighed an empty bowl and recorded its mass. Then she placed three ice cubes in the bowl and weighed it again. After the ice melted, she recorded the mass of the bowl and the water. She put the data in a table.

What conclusion should Veronica make from her observations?

• A. The masses of the water and the ice were both 43 grams, so the amount of matter did not change.

• B. The masses of the water and the ice were both 153 grams, so the amount of matter did not change.

• C. Some of the water spilled because the mass of liquid water should have been greater than the mass of solid ice.

• D. There was an error in weighing the ice because the mass of liquid water should have been less than the mass of solid ice.

A glass of ice water is placed on a table inside a room that is at room temperature. The ice inside the glass melts. The diagram represents the changes observed.

Which piece of evidence supports the conservation of matter during the changes shown in the diagram?

• A. The contents of the glass are wet before and after the ice melts.

• B. The combined mass of the glass and its contents is the same before and after the ice melts.

• C. The combined mass of the glass and its contents is less after the ice melts.

• D. The contents of the glass are colorless before and after the ice melts.

Chris fit the pieces of a space shuttle model together.

Which statement BEST describes how the pieces compare to the completed model?

• A. Each piece is stronger than the completed model.

• B. The mass of the completed model equals the mass of all the pieces.

• C. Each piece is made from a different material than the completed model.

• D. The mass of the completed model is more than the mass of all the pieces.