Water Works - - - - - - - - - - - - - - - - - - - - - - - - - - Water is all around us. It can be found in ponds, rivers, lakes and even in our bodies. It s also great for having fun! Transform your house into a laboratory and try your hand at a few scientific experiments with H 2 O. Explore how water molecules stick together and how they can make a gummy bear double in size. Discover how to filter dirty water and how to make a beautiful water rainbow!
Sticky Water Explore how water sticks together by counting how many drops of water you can put on the surface of a dime before the water overflows! It may be more than you think! two dimes two eyedroppers one cup of water one cup of water with 1 tbsp. of dish soap mixed in 1. Fill one of the eyedroppers with water. 2. Gently squeeze the top of the eyedropper and let the water drip, one drop at a time, onto one of the dimes. Count how many drops fit on top of the dime before some of the water starts to run off the coin. 3. Fill the second eyedropper with water that has some dish soap mixed into it. 4. How many drops of soapy water fit on top of the second dime? Is this number bigger or smaller than the number of drops of regular water? Water molecules are strongly attracted to each other and stick together, especially at the water s surface. This attraction between molecules at the water s surface is called surface tension and is so strong that the drops of regular water can keep on piling on top of each other to form a small dome of water on the dime. Since dish soap prevents water molecules from sticking together there are fewer drops of water that can accumulate on the surface of the dime before some of the water runs off the coin.
Absorption Rainbow How can you move water from one glass to another without lifting a finger? Watch as water climbs up sheets of paper towel to fill empty glasses and mix colours, making a liquid rainbow. 6 sheets of paper towel 6 glasses of approximately equal size food colouring (red, blue, yellow) water 1. Place 5-6 drops of red, blue, and yellow food colouring in three different glasses (one colour per glass). Add approximately 1 1 ½ cup of water in each of the three glasses. 2. Arrange the coloured water glasses to form the three points of a triangle. Place an empty glass in the space between each of the three points. 3. Twist each sheet of paper towel lengthwise. 4. Connect the glasses by placing one end of a paper towel sheet in an empty glass and the other end in a glass with coloured water. 5. Sit back and wait. The movement of water through the paper towel strips will take a few hours, so you may want to set the glasses off to the side and check in on them later. Paper towel is porous, meaning that between the paper towel fibres there are many small, empty spaces. When you observe paper towel absorbing water, you are watching water move through these small, interconnected spaces. As one water molecule moves up the paper towel, it pulls along other water molecules with it. Plants use this process to draw water up from the ground. Stage 1: The pieces of paper towels are leading the coloured water towards the empty cups. Stage 2: Each of the previously empty cups is receiving water of two different colours. Stage 3: Each of the previously empty cups receive water of two different colours. The colour pigments mix and make new colours (orange, purple and green).
Gummy Bear Osmosis Have you ever wanted to get bigger gummy bears? Try soaking a gummy bear in water overnight to see if water alone can change its size! (Sadly, though, the taste is unlikely to improve.) a shallow bowl or plastic container gummy bears water a spoon a plate 1. Take out two gummy bears. Put one of them on a plate and store it in a safe dry place. 2. Put the second gummy bear into a shallow bowl or plastic container. Pour enough water into the container to completely cover the gummy bear. 3. Wait 24 hours. After 24 hours have passed, use a spoon to gently lift the gummy bear that was submerged in water out of the container and place it on the same plate as the other gummy bear. 4. Compare the size of the two gummy bears. Water molecules always move from an area where there is a lot of water molecules to an area where there is less. In this experiment, the water in the bowl of water wanted to move inside the gummy bear because there isn t that much water in the candy. The movement of water molecules into the gummy bear results in its increase in size. This process is called osmosis and is used by plants to take up water through their roots.
Water Filtration The water that comes out of the tap at home and at school has gone through a long cleaning process to make it clear and safe! Build this model to see how soil and plant material are removed during the water treatment process. a clear plastic water bottle an elastic band a paper coffee filter cotton balls sand gravel small rocks or marbles a glass of muddy water (you can take water from a river, lake or use a mix of water and dirt) a transparent jar or container scissors Do not drink the filtered water. Invisible, harmful bacteria may still be present in the water. 1. Carefully cut the bottom off of the plastic water bottle. 2. Push 1 to 2 cotton balls into the neck of the bottle. 3. Cut a 6 cm 6 cm piece of coffee filter paper and place it over the bottle neck. Wrap an elastic band around the filter paper and bottle neck to keep it in place. Turn the bottle upside-down. 4. Through the cut end of the bottle, pour in the sand to create an even layer over the cotton balls. Next create an even layer of gravel over the layer of sand. Finally, add a layer of small rocks or marbles over the layer of gravel.
Ready, Set, Filter! 5. Set your filtration system over the opening of a transparent jar. Slowly pour the muddy water onto the layer of small rocks or marbles in your filtration bottle. 6. Wait as the water flows through the layers in your filter and drips into the transparent jar. Is the filtered water any cleaner than the muddy water that you started with? Each of the layers in the filter stops particles of different sizes in the muddy water from passing through. The spaces between the small rocks or marbles are too small to for small twigs, leaves, and clumps of dirt to move through, so these materials are caught at the top of the filter. As the water seeps further down the filter, the spaces within the filtering materials (gravel, sand, cotton, and coffee filter paper) become smaller and smaller, allowing only water and very fine particles to pass through the entire filter into the transparent jar at the bottom.
For the Experiments two dimes two eyedroppers dish soap 6 sheets of paper towel 6 glasses of approximately equal size food colouring (red, blue, yellow) a shallow bowl or plastic container gummy bears (at least 2) a spoon a plate a plastic, see through water bottle an elastic band a coffee filter cotton balls sand gravel small rocks or marbles a glass of muddy water (you can take water from a river, lake or use a mix of water and dirt) a transparent jar scissors Movie Finding Nemo (Walt Disney Pictures, 2003) Book The Magic School Bus Wet All Over: A book about the water cycle by Nancy White (Scholastic Paperbacks, 1996) Web Link Suggestions To learn more about water in Canada, check out the following web site: http://www.canadiangeographic.ca/atlas/themes.aspx?id=watersheds&lang=en