Science at Home A guide to at home science experiments and activities for students and parents Tess Beem Bowdoin College Class of 2013
Hello! My name is Tess Beem and I am a senior at Bowdoin College. This past fall I took an Environmental Studies course called Environmental Education. Over the course of the semester I taught at Harriet Beecher Stowe Elementary School in Ms. Bailey s fifth grade class. During my time teaching I was overwhelmed by the enthusiasm and interest from the students in my lessons. From my personal experience, I found that I received the most positive response during hands on activities. As part of my final project, and my final contribution to Ms. Bailey s class, I have put together a broad array of at home science experiments and activities. Science and learning do not have to stop when a child leaves school. Through the use of this booklet it is my hope that students will be encouraged to keep asking questions and learning about the world around them. The goal of this booklet is to encourage science and learning outside the school environment. It is meant to be safe for children to do on their own or with the participation of a parent or sibling. The first two experiments, Slime and Ooze, are ones that the students have done in class. They should be familiar with the directions and know what the end product should look like. These experiments, for the most part, require materials already found in the home. They are low-cost and low-resource dependent. Enjoy! Please feel free to contact me at tbeem@bowdoin.edu with any questions or comments! 2
Table of Contents [ ] [ ] Slime (Cornstarch) 4 [ ] Ooze (Borax) 5 [ ] Salty Ice 6 [ ] Homemade Paper 7 [ ] Spy Ink 8 [ ] Avocado Tree 9 [ ] Rainbow Flowers 10 [ ] Tie-dye Milk.11 [ ] Layered Liquids 12 [ ] Candy Chromatography 13 Acknowledgments 14 Sources for Future Interest 14 References.14 3
(1) Slime (Cornstarch) Is it a liquid or a solid? This experiment explores viscosity and the states of matter. * 1/4 cup of cornstarch * 1/8 cup of water (about 2 teaspoons) * Food coloring * Mixing bowl * Newspaper 1. Cover your table or work area with newspaper. Collect all your materials. 2. Add ¼ cup of dry cornstarch to the bowl. 3. Add 2 tablespoons of water to the cornstarch and stir slowly. 4. Add water until the cornstarch acts like a liquid when you stir it slowly. 5. The substance should become hard when you touch it with your finer. If your mixture is too liquid, add more cornstarch. 6. The goal is to create a mixture that feels like a stiff liquid when you stir it, but feels like a solid when you touch it with your finger 7. In the palm of your hand, slowly work the substance into a ball, keeping pressure on it by rubbing it between your hands. It should stay solid. Stop rubbing, and it melts into your hand. Why does the cornstarch mixture behave like this? What happens in the cornstarch mixture is similar to walking on a busy sidewalk. The solid cornstarch acts like a crowd of people. By pressing your finger into the mixture, the cornstarch moves out of the way. But when you tap the mixture quickly the solid cornstarch particles don t slide past each other and out of the way of your finger. Viscosity is used to describe the resistance of a liquid to flow. Water, which has a low viscosity, flows easily. Honey has a higher viscosity than water and flows more slowly. Warming honey up decreases its viscosity so it flows more easily. 4
(2) Ooze (Borax) Explore science with gooey ooze! Learn about polymers and how molecules interact. * 1/4 cup of water * 1/4 cup of white craft glue (like Elmer's glue) * 1/4 cup of liquid starch (Borax) * Food coloring * Mixing bowl * Mixing spoon * Newspaper 1. Place a sheet of newspaper flat on a table. Put the mixing bowl in the middle of the newspaper. 2. Pour all of the glue into the mixing bowl 3. Pour all of the water to the mixing bowl with the glue. 4. Stir the glue and water together. 5. Add your food color now - about 4 drops should do it. 6. Now add the liquid starch (Borax) and stir it in. 7. It should be nice and blobby by now. As you play with your slimy concoction, it will become more stretchy and easier to hold. 8. Explore your slimy creation and store it in a zip bag when you are not using it. Glue and water mix to form a polymer. This is a long chain of molecules stuck together. When you add the Borax the strands of the polymer glue hold together, giving it its slimy feel. Other examples of polymers include: plastic soda bottles, Jell- O, and gum. Tip: Keep your slime in a tightly closed plastic bag when you are not playing with it, and keep it away from carpet and your little sister's hair. Larger batches can be made, just mix equal parts glue and water, with the appropriate amount of Borax. 5
(3) Salty Ice Why do they sprinkle salt on the ground in the winter? Use this fun experiment to learn why! * Ice cubes * A piece of string * A cup of cold water * Table salt 1. Place several ice cubes in your glass of water. 2. Dipping the string into the cup, try and remove the ice cubes. Not working? 3. Now, try draping the string over several of the ice cubes and pouring salt on top. Let the string sit like this for a minute or two. 4. Pull the string out of the class of water. Did you catch any ice? Salt lowers the freezing and melting temperature of water below the normal 32 degrees F. The salt melts the ice near the string and the surrounding water refreezes around it. This is what allows you to pull the ice out using only the string! 6
(4) Homemade paper This is a great activity to learn about recycling and make a beautiful end product! * Paper products: construction paper, paper towels, magazines, or newspaper, just nothing with waxy coatings * Water * Blender * Decorations (optional): flower petals, small leaves, seeds, foil, food coloring Making the frame: You don t need to do this if you want to make a rough paper without an edge. To form paper into a rectangle sheet using a frame: 1. Bend an old wire coat hanger into a rectangle (or other shape) and slip an old pair of pantyhose around it to act as a screen. 2. Put this aside until paper pulp has been made. Making the paper pulp: 1. Tear up paper into small pieces and put in the blender (mixing papers is fine!). Fill to the top, but don t pack it too tight! 2. Fill blender 2/3 of the way full with warm water. 3. Blend paper until the pulp is smooth and there are no lumps. 4. Place your mold/fame in a shallow basin (like a cookie sheet or the sink). 5. Pour the contents of the blender into the frame. 6. If you want to now is the time to add in your decorations! 7. Using a towel pat out any extra moisture. 8. Pat out the pulp until it is very thin (the thinner it is the quicker it will dry!). 9. Let the paper dry in the mold and then peel it off. 10. Now you have a beautiful gift or special piece of notepaper! 7
(5) Spy Ink Learn an easy way to become a spy. First step- writing like one! * A bag of cranberries * Baking soda * Paper * A small paintbrush or Q-tip * Old clothes Note: make sure the paper that you are using turns pink when dipped in the juice, not blue. Making the juice: 1. Have an adult or older sibling boil the cranberries in ~3 cups of water for 15-20 minutes. Make sure the lid is on the pan! (some might explode) 2. Crush the boiled berries and collect the juice through a sieve or colander. 3. Allow the juice to cool. Then pour it into a baking sheet or pan at least as big as your piece of paper. Making the ink: 1. In a separate bowl, add 2 tablespoons baking soda to 1/3 cup warm water. Make sure the powder dissolves all the way. 2. Using your paintbrush or Q-tip, dip it into the baking soda solution and write a message on your paper. 3. Let your message dry completely. 4. Place your paper in the cranberry juice to reveal your secret message! Pigments in fruits change color when they are exposed to either acids or bases. Cranberries are extremely acidic, that s why they make your mouth pucker! The pigments in cranberries are red. Baking soda is a base. When the acid is added to the base it turns blue. That s how you are able to read your secret message! 8
(6) Avocado Tree A fun long-term project where you get to use the whole fruit- first you eat it, then you plant it! * Avocado (pit) * Toothpicks * A glass or small bowl 1. Remove pit from center of avocado (preferably after eating!). 2. Wash the pit and towel-dry. 3. Push three toothpicks about ½ inch deep into the thickest parts of the pit. These will suspend the bottom of the pit in water with the top half above. 4. Suspend the pit above a glass using the toothpicks. The toothpicks should be wider than the rim of the glass. 5. Fill the glass with water so that the bottom inch of the pit is submerged. Make sure the water level doesn t drop much this during the experiment. 6. Place the glass and the pit by a sunny window. Check the water level periodically. 7. In 3-6 weeks the pit will begin to sprout and roots will emerge. When the stem is 5-6 inches tall and leaves have sprouted it is time to re-plant the avocado! 9
(7) Rainbow Flowers A fun project that can be displayed around the house or given as a special gift! And there s science to explain it too! * Vases or cups * White flowers (preferably carnations) * Food coloring 1. Cut the ends off of the flower stems. This will help them suck up the water. 2. Place the flowers in cups of water (one cup for each color you want to make). 3. Squirt the food coloring into the water. Make sure you use enough to make the water a really deep color- the brighter the water, the brighter your flowers will be! 4. Let the flowers sit to absorb the colored water. Watch them over time to see how the color changes! If you look closely you can see how the color travels through the petals. Capillary action is what explains how the food color gets into the flower petals. This is the process where liquid flows into narrow, open spaces (like in the flower stems) even if it goes against gravity. That s how the colored water can flow UP into the flower petals. 10
(8) Tie-Dye Milk Just like washing the dishes, but SO much more fun! * A flat tray (like a baking pan) * Food coloring * Whole milk (not any other kind!) * Liquid soap 1. Pour the milk into the flat tray so that it covers the whole bottom. 2. Add several drops of your favorite color food dye into the milk at different spots. 3. Add about a drop of liquid soap on top of each spot of food coloring. 4. Enjoy the masterpiece! The whole milk has lots of fat in it. Just like the grease on your dirty dishes, the liquid soap attacks the fats in the milk. So, when you add the liquid soap it tries to break down the fat in the milk. In the process, the colors get scattered in an impressive show! 11
(9) Layered Liquids Have you ever noticed how oil and water don t mix, like in salad dressing? Well, this takes it to a whole new level! 5 to be exact! * ¼ cup corn syrup or honey * ¼ cup liquid dish soap * ¼ cup water * ¼ cup vegetable oil * ¼ cup rubbing alcohol * A tall glass or clear plastic cup * A cup for mixing * Food coloring (mix so you have 5 different colors) 1. In separate cups for each liquid, add food coloring. Each substance should be its own color. 2. Start by adding the corn syrup or honey to the bottom of the cup. Be careful not let any run down the sides! Fill the glass 1/6 of the way full. 3. Next, add the same amount of liquid dish soap. Go slowly so that it doesn t mix with the first layer. 4. Then comes the colored water. After the water comes the vegetable oil, and lastly the rubbing alcohol. 5. The layers should separate into unique bands of color. These substances have different densities. The liquids towards the bottom of the glass are more dense, or heavier, than the liquids found at the top. The density of a liquid is related to its position in the glass. 12
(10) Candy Chromatography Candies come in so many wonderful colors. They re as fun to experiment with as they are to eat! * A pencil * Coffee filter paper * Scissors * Ruler * 6 toothpicks * Aluminum foil * A tall glass * Table salt * Water * M&M or Skittles candies 1. Cut the coffee filter into a 3x3 inch square. Draw a line in pencil about ½ inch from one edge. Draw 6 equally spaced dots along the line. Leave ¼ inch between the first and last dots and the edge of the paper. Label each dot bellow the line with the color of each candy. For example: Y for yellow. 2. To remove the color from the candy: take a piece of tin foil and place it on the table. Place 6 drops of water along the foil, evenly spaced. Place one candy of each color on each drop on water. Wait several minutes for the color to dissolve in water. Dispose of the candies in any way you like, yummmm! 3. To spot the color onto the filter paper: wet the tip of a toothpick in one of the colored droplets of water. Touch it to the corresponding pencil dot for that color on the filer paper square. Use a different toothpick for each color and repeat until you have all dots done. 4. Let the dots dry on the filter paper. Repeat steps 3 and 4 two more times (3 coats of color of the filter paper). 5. Mix ¼ teaspoon salt with 3 cups water. Pour the solution into your tall glass. 6. The level of the solution should not come above the line on the filter paper, so don t pour all of the solution in. Put the filter paper into the glass with the dots at the bottom. The color spots will begin to climb up the paper. 7. When the solution gets to ½ inch from the top, pull it out of the cup. Some colors are mixtures of other colors and will form different bands. Chromatography is the process where we separated the dyes into their individual components. Just like the rainbow flower experiment, it uses capillary action to help the solutions travel up the paper. 13
Acknowledgements I would like to thank my professor, Kara Wooldrik, for exposing me to the world of teaching. This class had made a drastic impact on my outlook on life and has influenced the direction of my life. I would like to give special thanks to Ms. Bailey for welcoming me into her classroom and allowing me time to teach her students. I would also like to thank all of my classmates from Environmental Education for their support and contribution to my work. They were a great soundboard during this experience. Finally I would like to thank the Bowdoin College Environmental Studies Department for their support and the opportunity to be a part of this course. Thank you. Sources for Future Interest 1. Your local schools, science departments and teachers 2. The activities sections of science curriculum books 3. Online blogs and data bases References Slime http://scifun.chem.wisc.edu/homeexpts/lumpyliquids.htm Ooze http://www.sciencebob.com/experiments/slime2.php http://www.sciencebob.com/experiments/polymer.php Homemade paper http://chemistry.about.com/od/chemistryactivities/a/howtomakepaper.htm Spy Ink http://kitchenpantryscientist.com/?p=2474 Milk and Color Blasts http://www.sciencebob.com/experiments/colorsymphony.php Layered Liquids http://www.youtube.com/watch?v=b3kodeqnqvu Candy Chromatography http://scifun.chem.wisc.edu/homeexpts/candy.htm 14