Understand Conservation of Matter Using Graphs

Which statement explains the change in mass?

• The painting is made of canvas and oil paint. Most, but not all, of the paint is on the canvas.

• Water vapor from the air condensed and mixed with the paint on the canvas. So, the paint gained mass.

• As Abigail painted her painting, she spread the oil paint out across the canvas. Because the paint was spread out, it lost mass.

Before she started painting, Abigail poured white, black, green, and yellow paint into four different cups. She poured 50 grams of paint in each cup. As she painted the hillside, she dipped a paintbrush into each cup of paint. When Abigail finished her painting, some paint was stuck to her paintbrushes and the cups. The painting had a mass of 350 grams. How much paint was stuck to the paintbrush and cups?

• 50 grams

• 100 grams

• 150 grams

• 200 grams

Which statement explains the change in mass?

• The pasta heated up while it cooked. Because it gained thermal energy, it gained mass.

• There was some water in the uncooked pasta, and that water evaporated. The cooked pasta did not contain water.

• While the pasta cooked, it absorbed some water. So, the pasta gained mass.

Complete the bar graph to show the mass of the water.

• The mass of the water after cooking is 500 grams (initial water) - 50 grams (vaporized) = 450 grams.

• The mass of the water after cooking is 500 grams (initial water) - 100 grams (vaporized) = 400 grams.

• The mass of the water after cooking is 500 grams (initial water) - 150 grams (vaporized) = 350 grams.

• The mass of the water after cooking is 500 grams (initial water) - 200 grams (vaporized) = 300 grams.

On Monday, Chase put a 50-gram ice cube in a 50-gram cup. Together, the mass was 100 grams. He left the cup at room temperature. When Chase came back on Thursday, he saw that the cup now had liquid water in it, not ice. The total mass of the water and cup was 70 grams. Which statement explains the change in mass?

• A) The ice cooled the cup down, so the cup lost mass. Then, the ice melted into water.

• B) The cup warmed up as it sat on the counter. Also, some water vapor condensed into the cup.

• C) The ice melted into liquid water. Then, some of the water evaporated.

On Monday, Chase put a 50-gram ice cube in a 50-gram cup. Over the next few days, the ice melted into liquid water, and some of the water evaporated. On Thursday, the 50-gram cup had 20 grams of water in it. How much water vapor was formed?

• 10 grams

• 20 grams

• 30 grams

• 40 grams

Francesca made a sand castle at the beach. She mixed 100 grams of seawater with 400 grams of sand to make a 500-gram mixture. She used the mixture to build a sand castle. When Francesca was done, her sand castle had a mass of 450 grams. Some sand was stuck to her hands. Which statement explains the change in mass?

• The sand castle is made of sand and seawater. Most of the sand and seawater is in the sand castle, but some of it is on Francesca's hands.

• The sand was cool when it lay on the beach. Then it warmed up in the sun, so it lost mass.

• All of the sand and seawater Francesca started with is in the sand castle. The sand on her hands is from somewhere else on the beach.

Francesca mixed 100 grams of seawater with 400 grams of sand and used her mixture to build a sand castle. When Francesca was done building, her sand castle had a mass of 450 grams. How much sand was stuck to her hands?

• 50 grams

• 100 grams

• 150 grams

• 200 grams

Monica set a cold, closed 70-gram bottle of apple juice on the counter. The bottle had a mass of 30 grams, and the apple juice had a mass of 40 grams. A few minutes later, she noticed that there were many small drops of water on the outside of the bottle. The total mass of the water drops and bottle of apple juice was 75 grams. Which statement explains the change in mass?

• There was water vapor in the air. Some water vapor condensed onto the cold apple juice bottle.

• There was water in the apple juice. As the bottle of apple juice warmed up, some of this water leaked through the glass to the outside of the bottle.

• Some of the apple juice evaporated and then condensed on the outside of the bottle.

Monica set a closed 30-gram bottle on the counter. The bottle held 40 grams of cold apple juice. Water vapor condensed on the outside of the bottle. After a few minutes, there were water drops on the outside of the bottle. Together, the water drops, the bottle, and the apple juice had a mass of 75 grams. What is the mass of the water vapor?

• 5 grams

• 10 grams

• 15 grams

• 20 grams