When You Pulled the Steel Wool Apart, You Found That the Mass Was Unchanged

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HW___ 6 Part Lab Summary- Mass and Change

1. When you pulled the steel wool apart, you found that the mass was unchanged. But, when you heated the steel wool, you found that the mass changed. Explain.

Draw diagrams (at the simple particle level) of the steel wool before and after the change.

Steel wool-pulled apart Steel wool-heated

before after before after

2. When ice melts, the volume of water is smaller than that of the ice. How does the mass of the water compare to the mass of the ice? Explain why?

Draw diagrams (at the simple particle level) of the ice and water. Use small circles to represent the H2O particles.

3. When the sugar dissolved in the water, you found that the mass remained unchanged. When the Alka-Seltzer dissolved in the water, the mass of the system changed. Explain.

Draw diagrams (at the simple particle level) of each of the materials before and after it was dissolved.

4. State the Law of Conservation of Mass in your own words.

5. If I start a chemical change with 10 particles of carbon dioxide (CO2 )

a. How many carbon atoms and how many oxygen atoms do I start with in the 10 particles? Explain your reasoning.

b. Based on the Law of conservation of Matter, how many carbon atoms and how many oxygen atoms do I end with after the chemical change? Explain your reasoning.

6. What does the Law of conservation of Matter tell us about the particles present at the start and after the explosion in the can demo?

Modeling Chemistry 1 U1 ws 1 v2.0