This is a hands-on activity exploring the properties of a substance called oobleck. Students will describe the substance. They will also design an aircraft that is able to land on the substance and then take off with out sticking to the substance.
Alabama Course of Study- third grade
#20 page 39: Describe observable properties of the states of matter.
#21 page 40: Students will describe characteristics of objects
As part of our lesson, we will be discussing how scientists work and how they develop ideas, etc. As a part of this, we will talk about the Mars Viking Project as an example. Scientists involved in this project examined the properties of an unknown substance—the red soil of the planet Mars. The Viking was a robot space probe and scientists used its camera to look at the surface of Mars. They took pictures of and examined the sand dunes, reddish-pink rocks, the consistency of the soil itself, and the atmosphere. A long robot arm on the front of the Viking was used to "touch" the surface and pick up soil samples. Remote control experiments were used to test the soil for Martian life forms. None were found. There was also an instrument that "smelled" the gasses of the atmosphere by studying the chemical make-up of the atmosphere. There was an antenna dish at the top of the spacecraft that sent information about Mars back to the scientists on Earth.
The Mars Viking Project was launched in 1975 and landed on Mars in 1976. In 1976 it was the most expensive space probes ever built. It contained five apparatuses to detect life on mars (referred to as the "senses" in the Oobleck Gems guide). These five "senses" were: a digital camera, a gas chromatograph/mass spectrometer (GCMS), a pyrolytic release (PR), labeled release (LR), and a gas exchange (GEX). Each spacecraft had two parts—a lander and an orbiter. The orbiters studied Mars from orbit for two years (the Viking I) or four years (the Viking II), sending images to Earth. The landers were only supposed to survive on mars for six months. However, the Viking II provided information for four years and the Viking I for six years. These were the longest surviving active labs on the surface of another world. In 1980, the Viking I was named the Mutch Memorial Station after Thomas A. Mutch, one of the chief scientists on the mission.
Some interesting facts:
It takes twenty minutes for an Earth signal to reach Mars.
The separation of lander from orbiter and landing sequence was done without ground control.
Several methods were used to slow the lander for a "soft landing." First, the heat shield absorbed heat as it decelerated due to atmospheric drag from entry. Six kilometers, or four miles, above the surface a parachute deployed and an aeroshell was jettisoned. One and a half kilometers, or five thousand feet, above the surface, three radar-controlled retro-engines fired to keep landers upright and to further slow it.
They landed at 2 meters/second (4.5 mph).
The missions found that carbon dioxide is a major component of the Mars atmosphere and nitrogen may have been more abundant in the past.
Viking I and Viking II found volcanoes, lava plains, immense canyons, cratered areas, wind-formed features, and evidence of surface water.
The surface material at the landing sites is best described as iron-rich clay.
Another aspect of this lesson is talking about the properties of substances. There are three states of matter—solid, liquid, and gas. Solids have tightly linked molecules, a fixed shape, and they occupy a certain amount of space or volume. These are the properties of solids. In liquids, molecules can slide past one another because they are more loosely held together. They flow and take the shape of the container they are in, and their volume stays the same in any container. Gas molecules can move in all directions and gas can fill any shape container, yet its volume is fixed. Matter changes state and takes on different properties when its temperatures rises or falls past a certain point. When you describe matter as a solid, a liquid, or a gas, you are listing a physical property of that matter. Physical properties help you identify something. You do not have to change the composition to observe physical properties. Some other physical properties are color, smell, taste, hardness, and the state of the matter (solid, liquid, or gas). Boiling and freezing points are also physical properties. Other physical properties are brittleness, the ability to be molded, etc. A physical property is a characteristic that can be observed without changing the composition of a substance. A chemical property is a characteristic that determines how a substance reacts with other substances. Chemical properties can only be detected if other substances are present as well. One chemical property describes whether or not a substance burns; others describe how a substance reacts with water and air.
Whole Class Materials:
- Plastic silver ware
The teacher must prepare the oobleck before starting the lesson. The recipe for the oobleck is:
Mix 15 drops of green food coloring with 4 ¼ cups of water. Poor the green water into a mixing bowl and add 4 boxes of cornstarch and another 2 ½ cups of water. Swirl and tip the bowl to level the contents, then place the bowl aside. At least 15 minutes before you plan to start the activity, mix the oobleck by hand to ensure an even consistency. Do not try to push through the oobleck mixture as if mixing batter, because that is very difficult. Instead, keep "lifting" the oobleck from the bottom of the bowl to the top by slipping your fingers under it until an even consistency is reached. Add more cornstarch or water to get the right consistency. Put the bowls aside until after you set the seen. Prepare the work area by putting the newspapers out and set up the equipment station.
For assessment, the students will create their own spacecraft and explain it. In doing this, they will demonstrate that they have an understanding of the properties of oobleck.
This showed how a teacher in Mississippi used the scientific method to investigate oobleck. She taught a third grade class and they covered each step of the method as they investigated the oobleck.
Alabama Course of Study- third grade
#1: Students will utilize techniques essential to scientific investigation.
-Developing new questions
-Selecting data samples
-Demonstrating critical thinking
-Predicting possible results
-Classifying objects, events, and organisms
#2: Exhibit habits necessary for scientific investigation.
-Attention to detail
July 24, 2000
When the first group came in, we invited them to sit down and we all introduced ourselves. I think that this is a good way to start off because it seems to put them more at ease. We then began the challenge of the day. The toothpick fish problem was a little bit difficult for the first group and I think some of the students were getting frustrated. I think we would have been better to think of another challenge that wasn’t quite so challenging, so that the children could start off the lesson with a little more success and a little less frustration. However, we weren’t really sure what to expect. But now that I look back, I think that it might be better to err on the easy side rather on the more difficult because I think the students may have loosened up quicker if they had some more immediate success. Besides, the toothpicks didn’t work real well on the newspaper-covered tables. However, I do feel that we handled it pretty well. I tried to walk around and help students, and by the third or fourth group I had developed a system where I moved the first toothpick for the student if they couldn’t get it and were getting frustrated, and then asked them to try and figure out how to move the last two. This seemed to work pretty well, and when the students figured it out, they still felt that they had done most of it since I had only moved one toothpick. The other problem with the challenge of the day was when we asked students to come up to the erase board and show how they solved it. I think doing it on the board was a little too abstract, and took too much time. I think it would have been better to have the other students gather around the one who is going to demonstrate and let him/her do it with the toothpicks. I also think that it is a good idea that you suggested to have the problem written out for them to take with them to work on at a later time. We could have had a copy of the problem and the solution and given it to one of the counselors and given them some toothpicks to take with them.
After the challenge of the day, I introduced the lesson by explaining that I had a friend from NASA who gave me some Oobleck from Mars and that we were going to try and figure out what it was and how to describe it. I liked this introduction, but I do agree that maybe we should have hammed it up a little more and made it more dramatic. To be honest, we did not think of that way to present it until that morning. We wanted to introduce it in a way that would get their interest and motivate them, and I think this story did (especially for the younger group). Making it more dramatic might have gotten the children even more excited. Having pictures of NASA or Mars, or maybe having someone play the part of a NASA employee might have helped.
Since the students were supposed to figure out the properties of the oobleck, we needed to explain what properties were. We used the example of a rubber ball and had them name properties that would describe that rubber ball. I think that another material might have been a better choice—the book suggested chalk. However, the students seemed to understand what we wanted from them. When we gave the students the oobleck, they loved it. A few seemed to only be playing with it (especially some in the second group), but many of the children were really trying to see what properties it had. I think all of the students would have discovered more about the oobleck if we had first given them just the bowls of oobleck and let them handle it. Then, after adequate time for exploring, give them a few utensils. After they had explored with the utensils, then maybe pose a question to the whole group for them to explore, such as: "Is it a liquid or a solid?" or "what happens when you leave it on the table?" Overall, however, they seemed to get a lot out of the exploration time. I heard lots of comments like, "This tuff is weird!" and "it’s soft, and then it gets hard!"
After cleaning up, we held a colloquium. It seemed to go pretty well. I had a hard time deciding what to write down—should I make a list of the properties, or should they just talk about them? I think the question about whether it is a solid or a liquid is a good one, except that they decide pretty quickly that it is both. I wish that the hot plate had worked so that we could have seen what happens to the oobleck when it is heated up—this might have helped further the discussion. I think that I should have explained the idea of designing a spacecraft a little more fully and had required them to write about their designs rather than saying that they could if they wanted to. This would have made them think more carefully about why they were choosing the design they did instead of just drawing a picture, which is what I felt many of the children were doing. I also should’ve stressed the importance of considering the properties of oobleck. Some of them had different conclusions as to whether or not certain materials stuck to or sank in the oobleck—maybe during the colloquium we could have done a little more experimentation and discussion and come up with a class consensus.
After designing spacecraft, if we had had more time, I would have liked to have each student show and explain their design and have students discuss the different designs that were used and why or why not they would work. This would have shown if students understood the properties of oobleck. If I were in a classroom, I would display the designs and then have the class act as a panel of scientists in which they would have to design one spacecraft. They could use different elements from different designs and it would be a wonderful way to have the kids practice working as part of a team.