Curriculum
Preschool Science Experiments
Preschool science experiments do not need beakers or lab coats. The best ones use household supplies, take less than 15 minutes to set up, and invite children to predict, observe, and talk about what happened. These 12 preschool science experiments are designed for mixed-age classrooms and fit easily into a center rotation or circle-time extension.
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Why add preschool science experiments to your week?
Science in early childhood is less about facts and more about habits: looking closely, asking questions, and testing ideas. A short preschool science experiment gives teachers a natural language-building moment and gives children a reason to write, draw, or describe what they saw.
The activities below are grouped by the science concept they highlight, but many touch on several ideas at once. Pick one that matches your theme for the week and adapt the vocabulary to your class.
12 simple preschool science experiments
1. Sink or float water bin
Materials: A clear bin of water, a towel, and a basket of small objects (cork, spoon, rock, plastic toy, leaf, coin).
How to run it: Before each drop, ask the children to predict: 'Will it sink or float?' Drop the object, observe together, and sort the items into two piles.
What they learn: Introduces density, buoyancy, and making predictions before testing.
Safety: Small items are choking hazards; supervise closely and do not use with children under 3.
2. Baking soda and vinegar volcano
Materials: Baking soda, white vinegar, a squeeze bottle, food coloring, and a shallow tray.
How to run it: Mound baking soda on the tray, add a few drops of coloring, then squeeze vinegar onto the mound. Watch the fizzing reaction and repeat with different colors.
What they learn: A classic acid-base reaction that also builds fine-motor control with the squeeze bottle.
3. Magic milk color dance
Materials: Whole milk, a shallow plate, food coloring, dish soap, and a cotton swab.
How to run it: Pour a thin layer of milk, dot food coloring around the surface, dip the swab in dish soap, then touch the milk. The colors swirl away from the soap.
What they learn: Shows surface tension and how soap disrupts fat molecules in milk.
Safety: Check for milk allergies first.
4. Ice melting race
Materials: Ice cubes, small plates, salt, warm water, and a timer.
How to run it: Give each child an ice cube and let them choose one helper: salt, warm water, or nothing. Predict which will melt fastest, then race.
What they learn: Teaches states of matter and how temperature and salt affect melting.
5. Magnetic sorting tray
Materials: A magnet wand and a mix of metal and non-metal objects (paper clips, blocks, crayons, keys, plastic lids).
How to run it: Children wave the wand over the tray and sort the objects into 'sticks' and 'does not stick' groups.
What they learn: Builds vocabulary around magnetism and classification.
Safety: Small items are choking hazards; supervise closely and do not use with children under 3.
6. Shadow tracing
Materials: Sunny window or flashlight, white paper, and small toys.
How to run it: Place a toy so its shadow falls on the paper. Trace the outline, then move the light source and trace again. Compare the two shadows.
What they learn: Explores light, shadows, and how distance changes size.
7. Dancing raisins
Materials: Clear cups, raisins, and sparkling water or club soda.
How to run it: Drop a few raisins into the cup and watch them sink, then bob up and down as bubbles attach and pop.
What they learn: A gentle introduction to gases, buoyancy, and observation over time.
Safety: Small items are choking hazards; supervise closely and do not use with children under 3.
8. Homemade lava lamp
Materials: A clear bottle, vegetable oil, water, food coloring, and effervescent antacid tablets (supervised).
How to run it: Fill the bottle two-thirds with oil and one-third with colored water. Drop in a small piece of tablet and watch the bubbles rise and fall.
What they learn: Demonstrates density and gas-producing reactions in a mesmerizing way.
9. Seed jar observation
Materials: Clear plastic cups, paper towels, bean seeds, and water.
How to run it: Wedge a damp paper towel against the inside of the cup, place a bean between the towel and the wall, and set in sunlight. Check daily for roots and sprouts.
What they learn: Plants life cycles, patience, and daily observation routines.
Safety: Small items are choking hazards; supervise closely and do not use with children under 3.
10. Static electricity butterfly
Materials: Tissue paper, a balloon, and a wool sock or hair.
How to run it: Cut a butterfly from tissue paper, charge the balloon by rubbing it on wool or hair, then hold the balloon near the butterfly. The wings lift.
What they learn: A safe, visible way to explore static electricity.
Safety: Balloons are a choking hazard. Adults handle balloons; discard broken pieces immediately.
11. Bubble prints
Materials: Bubble solution, washable paint, a bowl, and paper.
How to run it: Mix a little paint into bubble solution, blow bubbles onto the paper, and let them pop into colored circles.
What they learn: Combines art and science while exploring surface tension and air.
12. Color mixing lab
Materials: Small clear cups, water, and red, yellow, and blue food coloring.
How to run it: Set out primary colors and let children mix small amounts into empty cups to discover orange, green, and purple.
What they learn: Reinforces color theory and the idea that mixing changes properties.
Tips for a smooth science activity
- Prep ahead. Measure supplies into small cups or trays so children can start immediately and the teacher can focus on facilitation.
- Ask before showing. A quick prediction question — "What do you think will happen?" — turns a demo into a thinking exercise.
- Document with photos. Snap pictures of the reaction and print them for the science board or parent update.
- Keep it optional. Some children prefer to watch the first round. Let them join the next group once they feel ready.
- Clean up together. Pouring, wiping, and sorting tools is part of the learning.
Safety reminders for childcare settings
Always supervise science activities closely. Use non-toxic materials, avoid choking hazards for children under 3, and keep electrical or heat sources out of reach. If an experiment involves effervescent antacid tablets or food coloring, an adult should handle the tablets and direct hand-washing afterward.
Frequently asked questions
Are these science experiments safe for toddlers?
How long should a preschool science activity last?
What do children learn from preschool science experiments?
How do I set up a science center in my preschool classroom?
Do I need special supplies for these experiments?
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