Lesson One: Oobleck and Glurch (introductory lesson to promote curiosity and a driving question)
Time Frame: 40-45 minutes
Objectives:
-Students will observe the movement of Oobleck and Glurch and be able to relate that moment to that of solids and liquids.
-Students will be able to state the properties of solids and liquids and compare them to the properties of Oobleck and Glurch.
Materials: Oobleck -½ quart of water
2 boxes of starch
food coloring
Put the water and food coloring in a large bowl and begin adding cornstarch and mixing. Eventually the mixture will get thicker; keep adding and stirring. You will know when you have Oobleck
Glurch -water
White glue
Sodium borate
Food coloring
There are actually two solutions for Glurch. The first is 50% water, 50% white glue and food coloring. The second is a nearly saturated solution of sodium borate. (I would experiment to see how much you actually need. I usually just pour a couple tablespoons in a half-quart and shake.) Give the students equal volumes of the two solutions to mix.
Pie pans, newspaper (to cover desks), small objects (paper clips, pennies, confetti, marbles, toothpicks), Bartholomew and the Oobleck by Dr. Seuss
Procedure:
- Begin the lesson by introducing the principals? of solids and liquids. Write the students ideas on the board.
Liquid:
-assumes the shape of the container which it occupies
-is not easily compressible (little free space between particles)
-flows easily (the particles can move/slide past one another)
Solid:
-has a fixed volume and shape 9the particles are locked into place)
-is not easily compressible (little free space between particles)
-does not flow easily (the particles cannot move/slide past one another)
Have the students write these properties in their science journals.
- Use a model to demonstrate the molecular difference between solids and liquids. Cheerios work great for liquids – they roll around, take the shape of the container and aren’t bound to one another. Several legos stuck together are the perfect solid – they always keep their shape, are hard to touch, and stick together.
- Inform the students that it is possible for a substance to have both the properties of a solid and a liquid. Read the book Bartholomew and the Oobleck by Dr. Suess.
- Ask the students to describe ways in which we can tell solids and liquids apart. Ask the students what is something that is different in every solid and every liquid and how they could test that. They should come up with the following four tests:
- Push test – can you push into it?
- Pick up test – if you pick something up, does it all come up?
- Pour test – does it pour out smoothly, or does it just fall out in a clump?
- Shape test – does it keep the same shape?
Have the students make a chart of those rules so that they can test any new materials by seeing if they match. These should be written on the board along with in their science journal.
- Divide the students into groups of four. Have one student from each group gather the materials and then explain the activity. The students will be able to handle and explore the consistency of the Oobleck. Students will then be given objects to use with the Oobleck and observe what happens with each. The students will perform the four tests and record these results in their journals.
Note: The students will discover that the marble and penny sink in the Oobleck and the toothpick and string float in the Oobleck. Heavier objects will sink and lighter objects will float.
- Now distribute the two pre-Glurch solutions and mixing stick. Have the students create the Glurch and perform the test done on the Oobleck on the Glurch. The students should review the chart they made and decide whether they have a solid or a liquid. These results can be made in their journals.
- Now the students should clean up their mess and put their new substances in a bag in their backpack so it does not distract them from the rest of the lesson.
- The students should discuss as a class their results and what they observed about solids and liquids. The instructor can help them in obtaining these results:
- Oobleck is a non-Newtonian fluid. This means that when a small amount of force is used, it acts like a liquid, but when more force is applied, it acts like a solid. For instance, one can slowly put a spoon in Oobleck, but it is impossible to stir it quickly. Therefore it exhibits characteristics of both solids and liquids.
- Glurch is a polymer that the students were able to watch polymerize. By mixing the two liquids together and stirring a sticky, gooey ball was formed and this is the Glurch. Because the Glurch has water trapped in its polymer matrix, it also exhibits a lot of the characteristics of solids and liquids. Though it seems solid, it will actually pour very slowly and take the shape of its container, yet it sticks together and can all be picked up at once.
- Students should be able to understand that in science, things aren’t always what you expect and that everything does not fall into neat categories.
Assessment: Students will already have started a section on solids and liquids in their science journal, recording the characteristics of each and their observations of the Oobleck and Glurch. Then they will develop some driving questions about changes of the states of matter that we will begin to investigate.
Extension: Have the students make their own journals for this unit on changes of states of matter. They can be creative and use their imagination.
I think this a great lesson to emphasize, exactly your point – things aren’t always what you expect. I would however, ensure that they have concrete example of solids and liquids first, before they explore characteristics of the oobleck and glurch.
I was concerned about the number of activities that students would be engaged in this one lesson. Do you think they would be able to accomplish all of the above in 45 minutes?
Assessment: What would you be looking for in their journal reports?
Lesson Two: What’s In My Balloon? (teacher directed, build skills and understanding)
Time Frame: 30-40 minutes
Objectives:
-Students will understand the meaning of the words solid, liquid and gas
-Students will be given concrete experiences with solids, liquids and gases
-Students will understand that solids, liquids and gases are all forms of matter and matter is anything that takes up space
Materials:Paper, balloons, water, scissors
Procedure:
- The students will come to the science table, with their journals, in observation groups of four. The other students will work on decorating their science journal and another activity at their desks.
- Each student will be given a solid and liquid in a sandwich bag. They will be told to look at the solid and the liquid, comparing and contrasting them. The students will then write in their journals the characteristics of their solid and liquid. These might include for the liquid: soupy, wet, moves around and for the solid: hard, firm and stays the same. The students can discuss these in their groups.
- At the science table there will be pre-made balloons. Tell the students that they will be investigating the contents of the balloons and writing in their journals their observations and illustrations.
- The students will feel the frozen water balloon can cut the rubber off with scissors. Discuss with the students what they see and feel.
- The students will do the same with the water balloon, observing the properties of the water when it is in the balloon and as they pour it into the dish or bowl. Record these observations.
- The students will feel the balloon filled with air. They will let the air out and write their observations. Encourage the use of descriptive words such as “hard, invisible, wet, splashy,” etc.
- After all the groups have been to the science table discuss with the class as a whole the observations of all the groups. Compile these results on a large chart with the three headings of solid, liquid and gas. This will enable to students to use this as a resource when doing the other activities. It will also help them better understand the characteristics and differences between the three states of matter.
Assessment: The students will be assessed on their journals and discussion at the science table. Within their journals, their words to describe the balloons should be descriptive and their illustrations neatly drawn.