By Samira Mehta
Below are 5 cool DIY science experiments that simple, fun, and educational!
1. Learn how plants "drink" water
2. The wonders of oobleck
3. See the rainbow!
4. Make your own lava lamp
5. Make a hovercraft
1. Learn how plants "drink" water
Supplies:
● White flowers
● Scissors
● Cup or vase to hold the flowers
● Water
● Food coloring
The experiment: Using scissors, cut about an inch off of the end of the flower stems. Then, fill your cup about 2⁄3 of the way with water. Add about 10 drops of food coloring (any color of your choice). Stir the water and food coloring together, and place the flowers in the solution. Place your flowers in indirect sunlight, and watch them turn the color of the food coloring over the next 48 hours!
How it works: Over time, water will evaporate from the flowers and the leaves in the plant. As this occurs, an attractive force between water molecules draws water from the cup up into the stem to replace the water molecules that are leaving from evaporation. Water travels through tubes in the plant’s stem called xylem. The combined attractive force between water molecules, called cohesion, and the sticking of the water molecules to the walls of the xylem, called adhesion, is stronger than the downwards force of gravity. Because of this, water is able to travel upwards into the flower.
Because we put food coloring into the water, the food coloring will hop along for the ride up the stem and into the flowers, causing the white petals, stem, and leaves to become colored.
2. The wonders of oobleck
Supplies:
● 1 cup of dry cornstarch
● Large bowl
● Food coloring
● 1⁄2 cup of water
The experiment: Pour the cornstarch into a bowl and add 2-3 drops of food coloring. Slowly add water to the bowl, making sure to mix the contents with your fingers until the starch and water are well-combined. Now, try tapping the surface of your oobleck. It should feel solid. This time, try slowing dipping your fingers into the oobleck. It should act like a liquid and allow your fingers to easily move through the solution. Play around with the oobleck to see what it can do! What happens when you squeeze hard? What about when you release your grip? There are so many things that you can do test the limits of oobleck!
How it works: In the 1700s, Isaac Newton, one of the most prominent physicists of all time, identified properties of ideal liquids. The thickness, or viscosity, of these fluids remains the same, no matter the amount of stress applied to them at a constant temperature. Liquids that exhibit this property, such as water, are known as Newtonian fluids. Oobleck is known as a non-Newtonian fluid because its thickness changes depending on the amount of stress applied. It is made up of cornstarch molecules that are suspended in water. When pressure is applied to the oobleck, its thickness increases, making it feel hard when you squeeze or tap it. This is because the sudden pressure moves the cornstarch particles together. When you slowly dip your fingers into the oobleck, the cornstarch molecules have sufficient time to move away from your hand. This allows your hand to easily slide through the solution, as if it were water.
3. See the rainbow!
Supplies:
● Paper towel
● Colored markers
● Bowl
● Water
The experiment: Draw a line with a colored marker about about 2 inches from the bottom of the paper towel. Dip the end of the paper towel into a bowl of water, making sure that the end with the colored line is close to the water but not submerged. Watch as the water flows up the paper towel and the pigments in the colored marker begin to separate. You will likely see that purple colored markers separate into red a blue pigments, while green markers separate into blue and yellow.
How it works: The pigments in colored markers are often created by mixing several different colors together. When the water traveling up the paper towel reaches the colored line, the pigments dissolve in the water and are carried along with the water as it continues traveling up the paper towel. Pigments are made of molecules, which vary in size and weight depending on the types of atoms they are made up of. The different colored pigments travel at different rates because their molecules are different sizes. This causes the colors to separate as they travel up the paper towel. This technique is known as chromatography, and it has many applications in science, when someone wants to separate different components in a mixture.
4. Make your own lava lamp
Supplies:
● Empty 1 liter soda bottle
● 3⁄4 cup of water
● Vegetable oil
● Alka seltzer
● Food coloring
The experiment: After pouring the water into the bottle, fill the rest of the bottle with vegetable oil. Wait until the water and oil separate. Add 10-15 drops of food coloring. It will pass through the oil and mix with the water at the bottom of the bottle. Break the seltzer tablet in half and drop it into the bottle. Then, watch as your lava lamp comes to life!
How it works: The water and oil initially separate because water is much more dense than oil, so it will sink to the bottom of the bottle. The water and oil will not mix together because water is very attracted to itself. Because of this, a water molecule prefers to interact with other water molecules instead of oil molecules. When the seltzer tablet lands in the water, the citric acid and the baking soda in the tablet begin to react with each other, forming a gas. The gas is less dense than both the water and the oil, so it will float to the top of the bottle. As the bubble rise, they carry some of the colored water with them, giving the appearance of a lava lamp.
5. Make a hovercraft
Supplies:
● Hot glue gun
● Bottle cap
● CD
● Balloon
● Thumbtack
The experiment: Use the thumbtack to poke 8 holes in the bottle cap. Then, use the hot glue gun to glue the bottle cap to the center of the CD above the hole. Make sure that the reflective side of the CD is facing up. Next, blow up a balloon and stretch it over the bottle cap. Try sliding a normal CD around. Now see what happens when you tap the side of your hovercraft. It should be able to easily glide about the surface without the application much force, just like a hovercraft!
How it works: As the balloon deflates, the air travels through the holes in the bottle cap that were made by the thumbtack. This air will then flow under the CD in order to escape into the environment, creating a layer of air for the CD to float on. If you have ever played air hockey at an arcade, you have seen this mechanism in action. Hockey tables work by causing a layer of air to flow under the puck, allowing the pucks to travel easily across the table with little to no resistance between the surface of the puck and the table, also known as friction.
Sources:
1. https://www.thoughtco.com/how-to-make-colored-flowers-606178
2. https://www.exploratorium.edu/science_explorer/ooze.html
3. https://www.parents.com/kids/education/math-and-science/everyday-science-experiments/?page=2
4. https://sciencebob.com/blobs-in-a-bottle-2/
5. https://learning-center.homesciencetools.com/article/balloon-hovercraft-science-project/
Editor: Andrew Zheng