What your Preschooler will Learn in this Preschool Science Experiment

What happens to water in puddles - that water evaporates in air.

That just because they can't see the salt or sugar in the water, doesn't mean it's not there.

That anything dissolved in water will remain after the water is gone

What you will Need for this Preschool Science Experiment

A clear glass (you'll need to write on it)

Salt or sugar

Water

A spoon

A pen (or labels if you don't want to write on your glass)

What To Do

Step one: Mix up some sugar or salt water until the sugar or salt is gone.

Step two: Have your preschooler taste it. Even though they can't see the salt or sugar anymore, it's still there.

Step three: Mark the level of your salt or sugar water with your pen or label.

Step four: Put your cup in a warm place. Every couple of hours, have your preschooler note how the level goes down with your pen or label.

What Will Happen in this Preschool Science Experiment?

Over time the water will evaporate and leave the sugar or water crystals behind.

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.

• Connect science observations to real-world applications: "This is why bridges are built this way" or "This is how your body does that." Application makes science relevant.

• Science fear is learned, not innate. Preschoolers approach science with natural confidence — protect that confidence by keeping science joyful and low-stakes.

• The best science projects are the ones children generate themselves by noticing something in the world and asking why. Adult-imposed experiments are valuable; child-generated experiments are extraordinary.

Frequently Asked Questions

What everyday household materials are best for preschool science?

The essential preschool science pantry: baking soda, white vinegar, cornstarch, salt, sugar, food coloring, dish soap, and water. These materials enable: acid-base chemistry (baking soda + vinegar), non-Newtonian fluids (cornstarch + water = oobleck), color mixing (food coloring), surface tension (dish soap), crystal growing (salt and sugar), and density experiments (sugar solutions). Beyond kitchen supplies: magnets, a flashlight, a magnifying glass, and ice are the other essentials. The best science lab is an accessible kitchen shelf.

How do I build a child's science confidence when they get frustrated by unexpected results?

"Unexpected" is the word to use rather than "wrong" — in science, results that don't match predictions are the most interesting. "The result was different from what we expected — that means we discovered something! Let's figure out why." This reframe makes the unexpected result a success rather than a failure, because it produced a question worth investigating. Science confidence is built by treating all results as valid data, never as failure.

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

🎓 Skills Your Child Will Develop

• 💬 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.
• 🌱 Curiosity & Wonder — Science that feels like magic cultivates the sense of wonder that keeps children asking questions throughout their lives — the foundational attitude that drives all learning and discovery.
• 📏 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.

Does your preschooler wonder what happens to rain or snow after a storm? Do they understand about evaporation? With this fun and easy preschool science experiment, they will learn all about evaporation and what happens to rain and snow on hot days.

Questions to Ask Your Child

Use these open-ended prompts to extend the learning during or after the activity:

• "What do you think will happen before we try it?"
• "Was your prediction right, or did something surprise you?"
• "Why do you think that happened?"
• "What would change if we tried it with something different?"
• "Can you think of a place in real life where you've seen this before?"
• "What question does this make you want to answer next?"

There are no right or wrong answers to any of these questions. The goal is to keep the conversation going, model curious thinking, and give your child practice putting their experience into words.