Read & Learn. Read the provided article. Use the information in the reading to answer the questions on the task cards on your answer sheet.

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1 Read & Learn Read the provided article. Use the information in the reading to answer the questions on the task cards on your answer sheet. Make sure your answers in the correct spot on the answer sheet. M. Poarch science-class.net Permission granted to copy for non-profit, education use only

2 Density Every object on earth is made of atoms. Gravity pulls these atoms to the earth. You can measure the pull of gravity on an object we call that measurement weight. Density is how close together the molecules of a substance are or how much mass a substance has in a given space. If you have one cup of jelly beans and one cup of marshmallows the jelly beans have more mass there is more stuff compacted into the cup. The marshmallows are mostly air. If you put each of those cups in a microwave to melt the sugar and water that makes up the jelly beans would almost fill the cup to the top. The sugar and water that makes up the marshmallows would only fill the cup a little bit because marshmallows have less mass, they are mostly made of air. Materials with more density weigh more. A cup of jelly beans weighs more than a cup of marshmallows. Density is a measurement of how solid something is. Specifically it is the mass per unit volume of a substance. If you have two objects of the exact same size (volume), the more dense object will weigh more than the less dense object. So there are two things contributing to density: The mass of the atoms or molecules that makes up the material. The volume or amount of space the material takes up. If the molecules or atoms are packed in more closely, it will be more dense. For example, Styrofoam is a low density material. Even a large styrofoam container does not weigh much. The molecules in the Styrofoam do not have much mass and there is a lot of space between them. A brick, on the other hand, is much more dense. Even a moderate sized brick can be pretty heavy. This is because the molecules which make up the rock have more mass and are packed more closely together. & M. Poarch science-class.net Permission granted to copy for non-profit, education use only

3 1 2 What is WEIGHT? What is MASS? What is VOLUME? Two objects have the same volume. Object A has a mass of 10 g. Object B has a mass of 20 g. Which object has the greatest density? 3 4 Two objects have the same mass. Object A has a volume of 20 cm 3. Object B has a mass of 40 cm 3. Which object has the greatest density? Describe DENSITY.

4 Watch & Learn Watch the video at this link: Use the information in the video to answer the questions on the task cards on your answer sheet. Make sure your answers in the correct spot on the answer sheet. M. Poarch science-class.net Permission granted to copy for non-profit, education use only

5 1 2 Complete this sentence: Density is a combination of and. Density is a defining characteristic of a substance. What does this mean? 3 4 What does density predict? How do you calculated density? What is the formula?

6 Explore & Learn Observe the tank of water and soda cans. Use your observations to answer the questions on the task cards. Make sure your answers in the correct spot on the answer sheet. M. Poarch science-class.net Permission granted to copy for non-profit, education use only

7 1 2 The can of regular soda sinks in water. What does this observation tell you about the density of the can of soda compared to the density of water? The can of diet soda floats in water. What does this observation tell you about the density of the can of diet soda compared to the density of water? 3 4 Use the terms mass, volume, and density to explain why adding bubble wrap makes a can of regular soda float in water. Use your observations to infer why life jackets are made of lightweight material and are large.

8 Explore & Learn Again 1. Drop the marble in the cup of water. 2. Observe. 3. Add bubble wrap to the marble and repeat. Answer the questions on the task cards. Make sure your answers in the correct spot on the answer sheet. M. Poarch science-class.net Permission granted to copy for non-profit, education use only

9 1 2 The marble originally sunk in water. What can you say about the density of the marble compared to the density of water? After adding bubble wrap your marble floated. What can you say about the density of the Marble-and-bubble wrap compared to the density of water? 3 4 Density is the relationship between the mass of an object and its volume. When you add material to your sinking object, what do you change more, mass or volume? How does increasing the volume of an object affect its density?

10 Investigate & Learn Perform the investigation. It has TWO parts. Answer the questions on the task cards for part 1, for part 2, and then for the conclusion cards. Make sure your answers in the correct spot on the answer sheet. M. Poarch science-class.net Permission granted to copy for non-profit, education use only

11 Investigate & Learn Procedure Part 1 read the entire procedure before you begin. 1. Fill 2 clear plastic cups about 2/3 of the way with room temperature water. 2. Fill one dropper with cold water that has been colored blue. Poke the end of the dropper a little beneath the surface of the colorless room-temperature water. 3. While observing from the side, gently squeeze the dropper so that the cold water slowly flows into the room-temperature water. 4. Fill another dropper with hot water that has been colored red. Poke the end of the dropper a little beneath the surface of this same cup of room-temperature water. 5. While observing from the side, gently squeeze the dropper so that the hot water slowly flows into the room-temperature water. Hold a blank piece of paper behind the cups to help you see the colored water.

12 Investigate & Learn Perform the investigation. It has TWO parts. Answer the questions on the task cards for part 1, for part 2, and then for the conclusion cards. Make sure your answers in the correct spot on the answer sheet. M. Poarch science-class.net Permission granted to copy for non-profit, education use only

13 Investigate & Learn Procedure Part 2 read the entire procedure before you begin. 1. Fill 2 clear plastic cups about 2/3 of the way with room temperature water. 2. Fill one dropper with cold water that has been colored blue. Push the end of the dropper to the bottom of the cup of the colorless room-temperature water. 3. While observing from the side, gently squeeze the dropper so that the cold water slowly flows into the room-temperature water. 4. Fill another dropper with hot water that has been colored red. Push the end of the dropper to the bottom of the cup of the colorless room-temperature water. 5. While observing from the side, gently squeeze the dropper so that the hot water slowly flows into the room-temperature water. Hold a blank piece of paper behind the cups to help you see the colored water.

14 Part 1-1 Part 1-2 Color in and label areas of the cup to show where the colored hot and cold water ended up after you released them into the room temperature water. Describe the movement of the hot and cold water after each liquid was released. Part Part 2 - Color in and label areas of the cup to show where the colored hot and cold water ended up after you released them into the room temperature water. Describe the movement of the hot and cold water after each liquid was released.

15 Investigate & Learn After you have completed both Part 1 and Part 2, complete the conclusion cards/ M. Poarch science-class.net Permission granted to copy for non-profit, education use only

16 Conclusion - 1 Conclusion - 2 Which temperature of water is MOST dense? Which temperature of water is LEAST dense? Conclusion - 3 Conclusion - 4 If you went scuba diving, would you expect the water temperature to get warmer or colder as you dove deeper beneath the surface? What evidence do you have from your investigation to support this? During late fall and early winter, the water at the surface of a lake may suddenly get colder than the water below it. What do you think happens to this water? Use the word density to explain why this happens.

17 Check & Learn Check your understanding of density by answering the questions. Have your teacher check your answers before you move to another station. Make sure your answers in the correct spot on the answer sheet. M. Poarch science-class.net Permission granted to copy for non-profit, education use only

18 The density The density of an of object an object is is a) The mass a) The mass divided by the volume divided by the volume D = m/v b) The D = m/v volume divided b) The volume by the mass divided D by = v/m the mass c) The same as its weight D = v/m d) The same as the size of c) The same the object as its weight d) The same as the size of the object If two objects have the same volume but one has a greater mass, the one with greater mass a) Has a lower density b) Has a higher density c) Will float d) Will sink 3 If two objects have the same Density is a characteristic 1 mass but different volumes property of a substance. a) The one with the larger volume This means that the density of has the lower density water b) They must have the same a) Changes depending on the density volume c) The one with the larger volume b) Stays the same regardless of the has the higher density volume d) The one with the larger volume c) Is greater for a greater mass of is twice as dense water d) Is less for a smaller mass of water

19 The density An object of should an object float is in a) a liquid The mass if it is divided by the volume D = m/v b) The a) More dense than the liquid volume divided b) Less by dense the than mass the D liquid = v/m c) The same as its c) weight Lighter d) than The metal same as the size of d) Shaped the like object a ball A tiny piece of sand is very light but sinks in water. This is because a) Sand is a solid b) Sand is less dense than water c) There is more water than sand d) Sand is more dense than water Wood floats in water. If you measured the mass of the same volume of wood and water a) The water would have a greater mass b) The water would have a lower mass c) The mass of the wood and water would be the same d) The mass of the wood and water would both be 100 grams 3 The density of hot and cold 4 water are different mainly because a) The molecules in hot water move slower and are slightly closer together b) The molecules in hot water are larger c) The molecules in hot water move faster and are slightly further apart d) The molecules in cold water move faster and are further apart

20 Draw & Learn Draw & label a diagram to illustrate density. Make sure to include: Mass Volume Particles M. Poarch science-class.net Permission granted to copy for non-profit, education use only

21 Explore & Learn Some More 1. Drop a ball of clay into the water. 2. Form the clay into a shape that allows it to float. Answer the questions on the task cards. Make sure your answers in the correct spot. M. Poarch science-class.net Permission granted to copy for non-profit, education use only

22 1 2 What happened when you dropped the ball of clay in the water? Is the clay more or less dense than water? How do you know? 3 4 Sketch the shape you made from the ball of clay. What happened to this shape in the water? Explain what has to happen for the clay to float on water.