From artificial limbs to steel alloys, our world abounds with materials shaped by engineering and science. Many, including the “miracle fiber” Kevlar invented by Dupont chemist Stephanie Kwolek, were accidental discoveries. Even Silly Putty, that popular toy, came out of research to develop rubber substitutes during World War II.
In this activity from ASPIRE, the K-12 outreach program of the Society of Women Engineers (SWE), students in grades 1-8 will learn some serious materials science–and hit several national science standards–by using everyday items to create and investigate the properties of Funny Putty.
This activity was developed by the Oklahoma State University Student SWE Section, which conducts a state-wide workshop annually for up to 1,200 Girl Scouts.
Grade Level: 1-8 Preparation: 15 minutes
Activity Length: 15-20 minutes (elementary) and 45-50 minutes (middle school)
* Students will identify the properties of solids, liquids and gases.
* Colloids are mixtures which display the properties of more than one of these states. By creating and working with colloids, students will demonstrate similarities and differences between colloids and solids, liquids and gasses.
* Students make putty (a colloid) and use the scientific method to experiment with its properties.
* Optionally, students can use different glues and use the scientific method to test how the properties of the putty change.
NATIONAL SCIENCE EDUCATION STANDARDS (National Research Council)
|Science as Inquiry|
|A1. Develop abilities necessary to do scientific inquiry.|
|B1. Develop an understanding of properties of objects and materials. (1-4)|
|B1. Develop an understanding of properties and changes in properties of matter. (5-8)|
STANDARDS FOR TECHNOLOGICAL LITERACY (International Technology Education Association)
|The Nature of Technology|
|2. Develop an understanding of the core concepts of technology. (1-5)|
|Abilities of a Technological World|
|11. Develop abilities to apply the design proces|
BENCHMARKS FOR SCIENCE LITERACY (American Association for the Advancement of Science)
|The Nature of Science – Science Technology|
|B1. People can often learn about things around them by just observing those things carefully, but sometimes they can learn more by doing something to the things and noting what happens. (1–2)|
|B1. Scientific investigations may take many different forms, including observing what things are like or what is happening somewhere, collecting specimens for analysis, and doing experiments. Investigations can focus on physical, biological, and social questions. (3–5)|
|B1. Scientists differ greatly in what phenomena they study and how they go about their work. Although there is no fixed set of steps that all scientists follow, scientific investigations usually involve the collection of relevant evidence, the use of logical reasoning, and the application of imagination in devising hypotheses and explanations to make sense of the collected evidence. (6–8)|
|The Physical Setting – The Structure of Matter|
|D1. Objects can be described in terms of the materials they are made of (clay, cloth, paper, etc.) and their physical properties (color, size, shape,
weight, texture, flexibility, etc.). (1-2)
|D2. Things can be done to materials to change some of their properties, but not all materials respond the same way to what is done to them. (1–2)|
|D3. Materials may be composed of parts that are too small to be seen without magnification. (3–5)|
|D4. When a new material is made by combining two or more materials, it has properties that differ from the original materials. For that reason, a lot of different materials can be made from a small number of basic kinds of materials. (3–5)|
|Habits of Mind – Values and Attitudes|
|A1. Keep records of their investigations and observations and not change the records later. (3–5)|
|A2. Offer reasons for their findings and consider reasons suggested by others. (3–5)|
|A1. Know why it is important in science to keep honest, clear, and accurate records. (6–8)|
|Habits of Mind – Values and Attitudes|
|C2. Measure and mix dry and liquid materials (in the kitchen, garage, or laboratory) in prescribed amounts, exercising reasonable safety. (3–5)|
Matter exists in three states: solid, liquid, and gas, but sometimes a substance does not seem to fit in any of these categories. Is clay or putty a solid or a liquid?
In this activity, you will make putty and have fun investigating its behavior. You can stretch and pull it, or break it into pieces. You may be able to bounce it.
* Elmer’s Glue-All
* Sta-Flo Concentrated Starch
* Set Of Measuring Spoons
* Plastic Wrap
* Plastic Cups
* Popsicle Sticks
* (Optional) Food Color
* (Optional) Small Plastic Bags
Steps to Follow:
- For the lesson presenter: you may want to pre-pour the glue and starch into small cups for the students and allow time for students to wash their hands after this activity.
- Review the information in the background section.
- Cut an 8 inch piece of plastic wrap and place it on the table in front of you. You will use this to knead the putty. Later you will wrap your funny putty with this plastic wrap so that it does not dry out.
- Measure the starch and glue and pour them into separate small cups. Use twice as much starch (For example, measure 1 teaspoon of starch and 1/2 teaspoon of glue; or measure 1 tablespoon starch and 1 1/2 teaspoons of glue). You may have to experiment with the measurements – the drier the putty is, the easier it will form a ball and bounce on a hard surface.
- Pour the starch into the glue. You can add a drop of food color. Stir the mixture with a popsicle stick.
- As the mixture firms, you can remove it from the cup, place it on the plastic wrap and use your hands to mix your putty.
- Now have some fun! Try out these properties to see if your funny putty behaves this way. If you pull the putty slowly, does it stretch? If you pull it quickly, does it break? Does it bounce off hard surfaces? Does it pick up newsprint?
- If the putty is left exposed to air, it will become brittle. Wrap your putty in the plastic wrap or a small plastic bag.
- If you use other types of glue, the putty properties may not be the same. You can use the worksheet to record how different glues affect the putty.
|Words to Know|
Objects on earth can be classified as a solid, a liquid or a gas. A block of wood is a solid – so is a pebble. The wood molecules are spaced closely together forming specific patterns. If a wooden rod is placed in a square hole, the wood does not change its shape to match the square hole. No matter how hard it is squeezed or pulled, the molecules do not move closer together or farther apart. The object may break, but the molecules don’t move. (See image, below, left.)
When water is poured from a round container into a square one, the water will not retain its round shape. The water is a liquid. The liquid takes the shape of the square container. The liquid will not expand to fill a larger space. It cannot be made smaller by squeezing or pulling. The molecules do not move closer together nor farther apart.
Gases take the shape of their containers and expand or contract to fill the container. When a person takes a breath of air, air rushes down the bronchial tubes and tries to fill all the spaces in the lungs. A big breath makes it easier to feel the lungs expand, but a small breath fills ALL of the lungs, too. A gas can be expanded or compressed. The molecules can move closer together or farther apart.
In science and engineering, the word fluid refers to a liquid or a gas.
Although matter exists in these three states: solid, liquid, and gas, sometimes a substance does not seem to fit in any of these categories. A substance may behave or have characteristics of more than one of these states. Some materials like asphalt and lead initially act like a solid, but over long periods of time they begin to act like a fluid.
Is toothpaste a solid or a liquid? Actually, it has characteristics of both. If you leave the toothpaste tube cap off, the toothpaste remains inside the tube. The toothpaste does not flow out of the tube like a liquid. The toothpaste retains its shape and acts like a solid. When you squeeze the toothpaste tube, toothpaste flows out of the tube like a liquid. A certain amount of force must be applied to the toothpaste before it will move. Toothpaste acts like a solid and a liquid.
The words big, tall and gray can all describe the same object at the same time. The words big, tall and gray can describe both a building and a large rock formation. The words colloid and nonnewtonian describe different characteristics of substances like mayonnaise and the funny putty you are making in this experiment.
Colloids are mixtures of a substance suspended in another substance. The suspended materials are so tiny, only 1 to 100 nanometers (10-9 meters) long, that they do not sink to the bottom of the other substance. Materials like colloids resist small stresses but yield (move) with large stresses and begin to flow like fluids. Some examples of colloids are smoke (solid particles suspended in air), fog, mayonnaise, meringue and the funny putty that you will make in this lesson.
In 1678, Sir Isaac Newton formulated a law which describes the movement of fluids when a shearing force is applied (a shearing force occurs when you slide one thing over another). Today, scientists refer to liquids and gases which move according to that law as newtonian fluids. For newtonian fluids, the change in velocity is proportional to the amount of shear stress. Common liquids and gases which are newtonian include water, oil, mercury, gasoline, alcohol, air, helium, hydrogen and steam.
Fluids which do not follow that law are called nonnewtonian. An example of a nonnewtonian fluid is toothpaste, which does not flow out of the tube until a certain amount of force is applied by squeezing – not just any little force. You know from experience that if you squeeze a toothpaste tube just a little bit, the toothpaste will not come out.
The funny putty you make in this activity is an example of a nonnewtonian colloid. It takes a firm pull to make the funny putty stretch. What happens if you pull the funny putty very quickly? Does it break in two?
Scientists and engineers need to understand colloid behavior to produce or manufacturer plastics, rubber, detergent, paint, food products and paper. Even environmental scientists learn colloid behavior and how it affects fog, precipitation and soils.
Cislunar Aerospace, Inc., wings.avkids.com/Book/Flight/instructor/fluids-01.html, 1997-2001.
Shaw, D.J., Introduction to Colloid and Surface Chemistry, Butterworth & Co., London, 1970.
White, F.M., Fluid Mechanics (2nd Edition), McGraw-Hill Book Company, New York, 1986.
Graphics of rod, gas and liquid copyright and courtesy Cislunar Aerospace, Inc.
Society of Women Engineers ASPIRE outreach resources, by grade
Image of fog courtesy National Oceanographic and Atmospheric Administration
Image of whipped cream courtesy NASA Science’s Physics of Fog
Top image of military child of the month making funny putty at Kaiserslautern courtesy of the U.S. Army
Engineering Project Notebook For_____________________
Project: Funny Putty
Funny Putty Data Collection Sheet
|Glue||Stretch?||Break?||Bounce?||Pick up Newsprint?||Other Observations|