Your kids probably ask a lot of questions.
By asking why, how, or what, your kids are actually participating in their own mini science experiments.
Science is a system of thought. It’s a way for individuals to understand the way things work and to find solutions to problems facing the world today. Kids are naturally curious and learn by experimenting with their natural surroundings. It's important to teach your kids the scientific method at a young age so they can grow up with the tools necessary to think critically when they approach a new challenge in life.
Science can also be fun! Grow your kid's imagination and thirst for knowledge with these five science projects you can do at home together.
1. Make your own crystals
You can teach your kids about crystals and satisfy their sweet tooth at the same time. This delicious science experiment requires only a few ingredients and some patience. You'll be working with high heat, so it's also a good opportunity to teach your kids about oven safety.
- 2 cups water
- 3 1/2-4 cups sugar
- measuring cup
- 4 clean drinking glasses
- 4 pencils or coffee stirrers
- 4 pieces of cotton string, like kite string
- 4 paper clips
- pot or saucepan
- wooden spoon
- food coloring (optional)
- coffee filters or waxed paper
Sugar crystal candy, also known as rock candy, is made from a supersaturated solution of sugar and hot water.
- Tie one end of each piece of string to the middle of a pencil or coffee stirrer. Tie the paper clip to the bottom of the string. The string should be long enough to hang nearly to the bottom of the glass, but shouldn’t touch the bottom.
- Heat up the water in a pot on the stove to boiling and slowly add the sugar while stirring with a wooden spoon. By heating up water, it’s able to absorb more sugar than it would have been able to at room temperature. Make sure an adult is around to help or at least watch to make sure your children are safe around the stove and boiling water.
- Continue to add sugar slowly until you have added all of the sugar or until it starts to accumulate on the bottom of the pot and won’t dissolve in the water anymore. At this point, the water-sugar solution is saturated.
- Carefully transfer the solution to the drinking glasses (again, have an adult help with this part). Divide the water up equally between each glass. Now is the time to add a few drops of food coloring to each glass if you want colored rocky candy. You can put a different color in each glass, if you wish.
- Place the pencils with the prepared string over the glasses and allow the string to dangle into the solution. The paper clip at the end is to help weigh down the string and keep it straight.
- Set the glasses somewhere where they won’t be disturbed as they cool. You might want to place a coffee filter or a piece of waxed paper over top of each glass so dust doesn’t settle into the glasses. Don’t touch the glasses!
- Check on them each day until the crystals grow to the desired size.
The saturation point of water lowers as the water-sugar solution cools, so the water can’t hold on to that amount of sugar. The sugar will then precipitate out and crystalize on the string in the glass. While you’re waiting for the crystals to form, have your kids answer the following questions:
- Why do we need to heat up the solution?
- What does it mean for the solution to be supersaturated?
After a week or so, your crystals will be ready to enjoy.
2. Tornado in a bottle
This “tornado” in a bottle is one of the easiest ways to teach your kids about centripetal force. It’s an inward force that makes things move in a spiral pattern when it’s travelling in a circle.
- clean and empty clear plastic bottle with cap
- liquid dish soap
- Fill the bottle with water to about 3/4 full.
- Add a few drops of dish soap.
- Sprinkle in some glitter.
- Put the cap on tightly.
- Spin the bottle rapidly in a circular motion while holding it upside down by the neck.
- Stop spinning the bottle and observe a vortex forming in the water (you may need to try several times before you get it to work).
The water is spinning into a vortex due to a force called centripetal force. This means the water is being forced toward the center of its circular path. Tornadoes, hurricanes, and water spouts are examples of vortexes we see in nature.
This simple science experiment is a perfect complement to teaching your kids about the weather.
3. Flower power
How do plants drink water? Where does the water go? In this experiment, kids can discover how important the roots and stems are for plants to grow. You might want to save this easy science experiment for when your kids are learning about plants in school.
- 6 white carnations (fresher better than old)
- 6 plastic cups
- food coloring (many different colors)
- Fill each cup halfway with water.
- Add 30 drops of food coloring to each cup except for one. Leave that one as just plain water. Trim the end of each stem at an angle with a knife (this should be done by an adult).
- Put one flower in each cup and stir the water to mix the dye.
- Observe the flowers over the next 48 hours. Examine the whole plant, including the stems, leaves, and petals. You could even take pictures at different times to track the changes.
Water that evaporates from the plant’s leaves and petals creates a suction that pulls water up from the plant’s stem and roots. This is called capillary action. Your kids are sure to be amazed when the petals start changing colors. You may also notice some color changes in the stems. Have your kids answer the following questions:
- What’s happening to the water?
- Which part of the plant takes up water? Where are the roots usually located?
- What parts of the plant did the water travel to first?
- What happened to the flower in the cup without food coloring?
4. Grow your own bacteria
Whether you like it or not, bacteria are everywhere. They’re on your skin and inside your digestive tract. While some types of bacteria cause disease, many types of bacteria are extremely important for our survival.
In this experiment, kids learn that bacteria are everywhere.
- Follow the instructions that came with your petri dishes to prepare them with agar. Agar is a safe gelatinous substance mixed with some nutrients. Bacteria eat the added nutrients, but can’t digest the agar, so it stays together. The colonies of bacteria that grow on the agar can therefore be easily observed.
- Using the cotton tip, swab something in your house, like the shower, a TV remote, or the kitchen sink. Do this in various places in your house. Only use one cotton swab per surface. To make this more fun, you can even swab your cheek or between your toes.
- Take the lid off the petri dish and rub the swab over the agar a few times (be gentle). Then put the lid back on and seal the petri dish. Label all the petri dishes with what object or body part the swab came from. Place each petri dish in a ziplock baggie and seal closed.
- Put a drop of hand sanitizer gel in the center of one of your prepared dishes after you’ve swabbed it. Make sure to label this one, too.
- Leave the dishes in a warm area for a few days.
- Check the growth of the bacteria each day and describe the changes. To protect yourself from bacteria that could cause illness, don’t open the ziplock baggies or the petri dishes once they are sealed.
- When you’re done with the experiment, discard the sealed ziplock baggies with the petri dishes in the trash.
Have your child predict what will happen in each plate. What do they think will happen in the plate with hand sanitizer?
After a few days, the bacteria will grow into individual colonies. Different samples will produce different results. During this experiment, you will teach your kids about bacteria. You can also teach them about our immune system and how it works.
5. Heat absorption
Here’s another simple science project with useful, real world applications. After doing this experiment, your kids won’t ever question you again when you tell them to wear light-colored clothes before going out to play in the hot sun.
- 2 identical glass jars
- black paper
- white paper
- elastic bands
- Wrap the white paper around one of the glasses and use an elastic band to hold it in place.
- Do the same with the black paper and the other jar.
- Fill the glasses with the same amount of water.
- Leave the glasses in the sun for a few hours.
- Record the temperature in each jar.
Dark surfaces absorb more light and heat than light ones, so the temperature should be higher in the jar wrapped in black paper. Light surfaces reflect, rather than absorb light. Wearing white or light colors in the summer keeps you cooler.
The next time your kids ask you a question about how things work, turn it into a science experiment. They’ll eventually learn how to form their own hypotheses and come to their own conclusions. If you don’t have the time or the materials to run your own experiment, there are thousands of science demonstration videos available on the web to help satisfy your kids’ endless desire for knowledge.