Adler Planetarium & Astronomy Museum / NASA Interstellar Boundary Explorer Mission

Transcription

1 Adler Planetarium & Astronomy Museum / NASA Interstellar Boundary Explorer Mission FOUR STATES OF MATTER Introduction This kinesthetic science activity reintroduces participants to three states of matter (solid, liquid, gas), and introduces them to a fourth state of matter, plasma, and its connection to the Sun. It also demonstrates how the addition of energy can transform matter from one state to another. The activity reviews common examples of matter in each state, like liquid water and water ice, oxygen and carbon dioxide, and the Sun. Objectives After completing the activity, participants will be able to: Name four states of matter and give examples of each state of matter Describe characteristics of matter in each state State that heat energy transforms matter from one state to another Describe how the atoms of a substance act in each state of matter Audience Museum: General Visitors School: Grades 6-12 Lesson Duration minutes Materials Hats with negative charge tags fastened to them (see template) An equal amount of positive charge tags that can be safely fastened to clothing or worn around the neck (see template) A variety of pictures of matter in four different states 1 beaker or other clear glass container filled with water 1 empty, clear vacuum container used for food storage (filled with air) 1 beaker or other clear glass container containing a rock 1 empty clear container that is a different shape than the container holding the water A plasma ball or other plasma source (like a neon sign) or a picture of a plasma (like a plasma television) A picture of the Sun Pencils and paper o For Lesson Extension: Masking tape or painters tape Alignment to National Education Standards Physical Science - Content Standard B: -Properties and changes of properties in matter (5-8)

2 A substance has characteristic properties all of which are independent of the amount of the sample. -Structure and properties of matter (9-12) Solids, liquids, and gases differ in the distances and angles between molecules or atoms and therefore the energy that binds them together. In solids the structure is nearly rigid; in liquids molecules or atoms move around each other but do not move apart; and in gases molecules or atoms move almost independently of each other and are mostly far apart. Preparation Copy and cut out 10 proton badge templates. Cut or punch through the dotted line on the badge with scissors or a hole-punch. Cut out ten pieces of yarn so that they are long enough to fit over a person s head when knotted. String the yarn through the hole in the badges and tie them at the top. Copy and cut out 10 electron templates. Fasten the templates onto 10 hats. Cut out pictures of matter in each of the four states from magazines (enough for each participant to have at least one picture). Be sure to include a picture of the Sun. Set up the three beakers and plasma source on a cart or table o For Lesson Extension: Use tape to create an irregular amoeba-like shape on the floor where the demonstration will occur. The shape should be able to accommodate all the human atom volunteers if they stand close together Procedure 1. Explain that everything in the Universe is made of stuff. 2. Ask participants to name things made of stuff. 3. Explain that the scientific word for stuff is matter. Matter exists in different states. 4. Ask participants if they can name some of the states of matter. It is likely that participants will name three states of matter: solid, liquid, and gas. 5. Show participants a picture of the Sun. What state of matter is the Sun? 6. Tell participants that the Sun is in a fourth state of matter called plasma. (A common misconception is that plasma, the state of matter, is the same as plasma in blood. Make it clear that they are not the same thing, if necessary) 7. Ask participants to give examples of each state of matter. For instance, ice cubes are solid, drinking water is a liquid, and the air we breathe in and exhale (including oxygen and carbon dioxide) is composed of gases. The Sun and stars are plasma. Lightning and neon signs are examples of natural terrestrial and artificial plasma, respectively. 8. Refer to the beakers and plasma example on the table as examples of each state of matter. Discuss characteristics of matter in each state in regards to

3 their shape and volume. Define volume as the amount of space something takes up. 9. First, ask participants if each state of matter retains its shape or has a fixed volume. Look at the rock. Does it always keep its shape? Does it always take up the same amount of space? (Yes) Therefore, solids have a fixed shape and volume. 10. Ask participants the same questions about the shape and volume of liquid. Ask them to predict what will happen to the shape and volume of the water when it is poured into the empty container that is a different shape. Then, pour the water into the empty container to demonstrate that liquid can take the shape of its container. Does the water increase in volume to fill the space? (No, liquid has a fixed volume, but not a fixed shape. Use differently shaped containers with volume measurements on them to emphasize this point) Challenge question: What happens to the volume of water when it freezes? 11. Ask participants about the shape and volume of gas. Ask them to describe what happens to the gas inside the vacuum container as you pump it out. Then release the pump to demonstrate that gas takes both the shape and volume of its container. 12. Tell participants that plasma is not a solid, liquid, or gas, but that it has some of the characteristics of gas and liquid. Look at examples of plasma, including the picture of the Sun. It can flow like a liquid, but its atoms are separate, like those of a gas. Its unique characteristic is its electric charge, which we will discuss later. 13. Distribute magazine pictures of matter in each state. Ask participants to work together in groups to categorize the matter as a solid, liquid, gas, or plasma based on its characteristics. Discuss the choices participants made to reinforce the characteristics of each state of matter. 14. Ask participants if matter can change from one state to another. What state of matter is an ice cube? What happens if you leave it on the kitchen counter? What state of matter did it become? What would happen to the water on the counter if you didn t clean it up (just like a puddle on the sidewalk)? The ice cube melts to become a liquid, and the puddle on your counter (or your sidewalk) evaporates it becomes a gas (water vapor). 15. Ask participants what changed the ice cube from a solid to a liquid, and the water from a liquid to a gas. (Heat energy!) 16. Tell participants that to demonstrate how this process works, you will need 10 of them to volunteer to be atoms. (Scale the number of volunteers to the demonstration space and crowd, if necessary) If they have never heard the term atom before, explain that this is the science word atom and not the boy s name Adam. 17. After you have picked your volunteers, line them up so that they face the rest of the participants. Explain that all matter is made up of atoms. Atoms are the

4 tiny building blocks that make up all matter. Explain that each volunteer represents an atom of some type of matter. 18. Explain that atoms are normally neutral. They do not have an electric charge, although they do have positive and negatively charged parts called protons and electrons. Distribute a negative electron hat and a positive proton badge to each volunteer. Explain that as long as the atoms are wearing both the positive badges and negative hats that they are neutral - their charges balance each other. 19. Instruct the human atoms to link arms. Those are the chemical bonds that keep the atoms together. Remind them that they represent the atoms in some type of matter in a certain state. Tell them that when you say, Go, they are to start moving around while keeping their arms linked together. When you say, Stop, they must stop in place. 20. Tell the human atoms to go. Allow them to move, with their arms linked, for about 5-7 seconds before instructing them to stop. Then, ask participants how difficult it was to move when they were linked together through their chemical bonds. Finally, ask which state of matter they thought they simulated (solid). What is their charge? (Neutral; nothing happened to the proton and electron) What are their characteristics? Could they change their shape or volume without letting go of their hands? (No. They have a fixed shape and volume). Lesson extension: Ask participants if they could they change their shape and volume to fit in the entire container outlined in tape on the floor? (No) 21. Explain that you are now going to add some more heat energy to the atoms. This heat energy makes the atoms more excited, which loosens their bonds. 22. Ask the human atoms to unlink their arms and to hold hands as a result of the heat energy loosening their bonds. Remind them to keep holding hands while they move around, and to stop when you say, Stop. 23. Have the human atoms move around, holding hands, for about 5-7 seconds after you say, Go. Ask them to stop. Then, ask participants how difficult it was to move now that their chemical bonds were loosened by the heat energy. What were their characteristics? Could they change their shape now that their bonds are looser? (Yes) Did the total amount of space they took up change each time they moved? (No, their volume stayed the same). Finally, ask which state of matter they thought they simulated (Liquid). What happened to the charge? (Nothing; still neutral due to the presence of the proton and electron) Lesson extension: Ask participants to move, without dropping hands, to fit in the container outlined in tape on the floor. Can they fill it? (Yes) 24. Tell the participants that you are adding even more heat energy to the atoms. This causes their bonds to break, and they become even more excited. Explain that when you say go, the human atoms are to drop hands and move

5 freely, but carefully, around the room. They must stop in their place when you say, Stop. 25. Say, Go, and allow the human atoms to move about the room for 5-7 seconds or so before saying, Stop. Then, ask participants how difficult it was to move now that their chemical bonds were broken by the heat energy. Finally, ask which state of matter they thought they simulated (gas). What characteristics of gas did they observe? (The gas filled the whole room. It did not have a fixed shape or volume. Which state of matter took up the most space? (Gas) Why? (The atoms are no longer bonded together due to the heat energy and can move farther apart) What happened to the charge? (Nothing; still neutral due to the presence of the proton and electron) Lesson extension: Ask participants to imagine that the gas atoms are being squeezed together and must move to fit in the container outlined in tape on the floor. Can they fill it? (Yes) What happened to the volume of the gas when the atoms were squeezed into the container? (They now have less volume, which shows that gas does not have a fixed volume) 26. Explain that you are going to add even more energy to the human atoms. This added energy causes them to lose their negatively charged electrons. When you say, Go, they will take off their hats, which represent their electrons, and place them on the floor. They will continue to carefully move around the room until you say, Stop. 27. When the human atoms stop moving at your command, ask participants to look around the room. What do they observe? (Electron hats on the floor and human atoms wearing protons spread throughout the room). What happened to the atoms? (They lost an electron) What is their charge? (They are now positive) Explain that when atoms lose an electron and become positive, they are now called ions. The process in which they lose electrons due to heat energy is called ionization. Plasma is an ionized gas. Ask, Is there the same number of electron hats as there are proton badges? (Yes) The loose electrons and ions make up the plasma in equal numbers. 28. Explain that plasma is a very common state of matter in the Universe. In fact, plasma from the Sun helps form a protective boundary around our Solar System. A NASA mission called IBEX, the Interstellar Boundary Explorer, will make a map of the Solar System s boundary. This will help us learn more about it. (To learn more about the IBEX mission, please visit Finally, thank the human atoms (now ions) for their help, and lead all the participants in a round of applause before asking them to hand in their hats and badges and return to their seats. Assessment 1. Finish the demonstration by asking questions and doing an activity that assesses whether participants can do the following:

6 o Name four states of matter o Give examples of each state of matter o Describe that heat energy transforms matter from one state to another o Describe characteristics of matter in each state o Describe how the atoms of a substance act in each state of matter Sample Questions: o What are the four states of matter we discussed? o Which state of matter took up the most volume, or space? o Which state of matter has a fixed shape? o Which state of matter has a fixed volume, but not a fixed shape? o What is an example of each state of matter? o What causes the matter to change from one state to another? o What are the atoms doing in each state of matter? What causes them to act differently? o Challenge: We have transformed our human atoms from one state of matter to another by adding heat energy. What might we do to transform a gas to a liquid, etc.? Assessment Activity: Ask participants to draw the atoms in each state of matter. Ask them to label each state.

7 - 1. Template for Electron to Fasten on a Hat

8 Template for Proton Badge +