Make Slime

Make slime with this easy preschool chemical reaction. Mix white glue (not washable) with an equal amount of water. In a separate container dissolve about two tablespoons of Borax (look in the laundry section of the store) with about a cup of water. Then add a few tablespoons of the Borax solution to the glue solution and stir quickly. Slime will form. Check my blog for pictures of the slime I created with my sons and for more information about this preschool chemical experiment.

Fun with Baking Soda and Vinegar or Lemon Juice

This is a very basic preschool science experiment, but it produces great results. Just combine baking soda and vinegar or lemon juice and stand back. Your preschooler will love the effect. This is the chemical reaction used if you want to build a volcano with your preschooler. For variation, try this preschool science experiment using a small and empty soda bottle and then put a balloon over the neck of the bottle. Because this preschool chemical reaction produces gas, a balloon will actually inflate.

Food Coloring Fun

Drip a few drops of food coloring into a clear glass of water. While there isn't a huge preschool chemical reaction, your preschooler will enjoy seeing the food coloring diffuse in the water. If they're old enough, you can teach them that this reaction is called diffusion.

Make Glop

Create glop with your preschooler with two easy substances in your kitchen. Mix equal amounts of cornstarch and water. The resulting substance will become thick, goopy and oddly hard. The goop is somewhere between a liquid and a solid. Roll up your preschooler's sleeves as they play with this preschool chemical reaction.

Lemon Juice Writing or Disappearing Ink

Let your preschooler paint a picture with lemon juice. When the paper dries, your preschooler's art will have disappeared. Then you'll want to paint the paper with iodine to make their drawing reappear. While you can use a candle or a flame to create the same preschool chemical reaction, using a candle around a preschooler is not recommended.

Milk Curdles

Add a few drops of vinegar to a bowl of milk and watch the milk curdle. Use a straw or a toothpick to pick up the curdles to show your preschooler. With this simple preschool chemical reaction, you've actually created curds and whey from the nursery rhyme Little Miss Muffet. Make sure you throw the milk away and don't let your preschooler drink it; it may make them sick.

Levels of Liquids

In a clear glass, add about a quarter to half a cup of water. Add a few drops of food coloring to it so you know which level is water. Slowly add about a quarter to half a cup of corn syrup to your water. It will float through the water to the bottom. Next add about a quarter to half a cup of oil. The oil will form a layer on the top. Corn syrup is the heaviest, so it floated to the bottom with oil staying on the top. This is a fun chemical experiment to do with a variety of liquids. Try to form other layers using vinegar and other substances (add the other substances extremely slow so they don't mix with the water or oil).

Hi! I'm Theresa Halvorsen, the preschool science and nature writer for Preschoolrock.com. I have twin boys and am blown away by their fascination with preschool science and how the world works around them. I am always looking for fun and simple science activities so preschoolers can learn about science and the natural world. Please contact me with any suggestions, ideas or questions you have about this site.

Helpful Tips for Parents

• Use correct scientific vocabulary from the start: observe, predict, experiment, hypothesis, result, evidence. Children absorb vocabulary in context without explicit teaching.

• Give children real tools: a real magnifying glass, real measuring cups, a real thermometer. Toy versions deliver less sensory and intellectual feedback than actual instruments.

Frequently Asked Questions

How do I keep science learning going between experiments?

Science is a mindset, not a schedule. Keep a magnifying glass accessible for impromptu investigation. Ask "why do you think...?" during daily life. Notice scientific phenomena out loud: "Look at how steam rises from the soup — where does it go?" Maintain a simple nature observation area (a window bird feeder, a terrarium, a weather chart). The child who develops the habit of curiosity about the physical world is doing science continuously, not just during scheduled experiments.

Related reading: See also our weather science and our bubble experiments for more ideas on this topic.

🎓 Skills Your Child Will Develop

• 🔬 Scientific Method — Even a simple experiment teaches the predict-test-observe cycle that is the foundation of scientific thinking — and preschoolers who internalize this process approach problems with genuine scientific confidence.
• 💬 Science Vocabulary — Science introduces children to precise vocabulary — observe, predict, hypothesis, dissolve, absorb, transparent — that dramatically expands language range and supports the academic vocabulary children need in school.
• 📏 Early Math & Measurement — Measuring ingredients, comparing quantities, and observing size changes connects science directly to mathematical thinking — making science experiments some of the richest early math experiences available.
• 🏗️ Engineering Thinking — Testing structures, materials, and designs to see what works develops engineering intuition — the practical understanding of forces, materials, and design that underlies all physical construction and problem solving.

Looking for some easy chemical reactions you can do with your preschooler using household ingredients? All of these preschool chemical experiments are done with safe and common household objects, with no flame or heat required. While these preschool chemical reactions may be a little bit messy, your preschooler will learn a great deal about how to combine two different ingredients to create a totally different substance and the beginnings of chemical reactions.