Water Experiments for Preschoolers: How to Make Science Simple


Many teachers tell me that they are not comfortable teaching science to young kids. They just don’t know where to begin. You don’t have to be a science expert to teach simple science concepts to preschoolers.

Simple Science Activities

Many teachers tell me that they don’t have supplies to teach science to their kids. I’m here to tell you that you can teach science concepts with some common household items.

water experiments for preschoolers that are simple and easy

In fact, I’m going to show you several investigations, easy science projects, or experiments you can do with water. They will be a great addition to your science center. You can even use the scientific method to conduct these simple water experiments for preschoolers.

Do you want the Free Printable Guide? All of the printables pictured below, along with the directions are currently available in my Fun & Easy Experiments with Water guide. Scroll to the bottom of the post to request your guide.

Experiment #1: What Holds Water Experiment?

This activity will help your kids learn about the properties of liquids in a fun way.

A liquid is a form of matter. When you pour a liquid into a container, it moves to form the shape of the container. Your kids can test the effectiveness of containers to hold a liquid (water).

child holing a glass of water and getting ready to do an experiment

Provide a variety of containers. Be sure to provide some containers that hold water and some that do not. Here are some suggestions:

  • small paper bag
  • plastic condiment cups
  • plastic cups – deli containers (some may have cracks)
  • muffin liners
  • coffee filters
  • plastic bags (some may have holes)
  • peat pots
  • plastic bottle caps
  • small cardboard box
  • a basket
  • a strainer
  • a juice box with the top cut off

You will also need a pitcher of water and a small tub to hold water that will leak out of some of the containers.

Begin by pouring water into a container and telling your kids that water is a liquid. When something is a liquid, it doesn’t have a set shape. Instead, a liquid forms the shape of the container that holds it.

Some containers do an excellent job of holding a liquid, and others do not. Today, we are going to investigate to find which containers are the best at holding water.

Make Observations

Let your kids look at the different containers and discuss which ones will hold water and which will not.

materials for a preschool water experiments

Form Questions

What makes a container suitable for holding liquids? What makes a container bad for holding liquids? How will we conduct a test? How will we know if a container is effective?

Develop a Hypothesis

Before testing the containers, kids can make predictions about whether they will hold water effectively. Use the sorting mats to sort them.

Experiment to Test Hypothesis

Place a container in a plastic bin and then pour water into it. Was the prediction correct?

simple preschool water experiment with a plastic bag

Some containers like this cardboard box may hold water in the beginning but may fail over time. Discuss this with your kids. They may want to classify the container as being effective or they may want to check them next day to see if they are still holding water.

a simple preschool science experiment with water and a cardboard box

Record, Share, & Discuss Results

After testing all of the containers, sort them again on the sorting mats. Where there any surprises? Are there similarities between the effective containers? Are there similarities between the ineffective containers?

collecting data for a preschool science experiment using water

Experiment #2: Does the Boat Sink or Float?

This activity put a bit of a twist on the traditional sink or float test. Your kids will be able to investigate the properties of matter as they conduct an experiment to see if their boats will sink or float.

Begin by filling some small plastic containers with a variety of materials. The containers should be seal tightly so that the contents inside do not get wet. Small containers from the dollar store or small reusable plastic food storage containers work well.

Be sure that you provide some materials that will float and some that will sink. Want some ideas for materials to use? You can find lots of ideas in this article about comparing weights with a balance scale.

An easy water experiment about sinking and floating for preschoolers

You will also need a clear plastic tub filled with water. The water should be deep enough so that the small containers will be underwater when they sink.

Explain to your kids that you will pretend that each of the containers is a boat, and you are going to figure out which boats will sink and which boats will float.

Make Observations

Let kids examine the boats and talk about the materials they see inside each container.

Form Questions

Do you think that all of the containers will float? Why or why not? Do you believe that all of the containers will sink? Why or why not? What makes a boat sink or float?

Develop a Hypothesis

Before adding the containers to the water tub, ask kids to make predictions by sorting the boats on the sorting mats.

Recording data in the easy water experiment for preschoolers

Experiment to Test Hypothesis

Kids can test their hypothesis by placing each boat into the tub of water. Does it sink, or does it float? Did any of the results surprise you?

A container of water with a sinking container to observe during water experiment for preschoolers

Record, Share, & Discuss Results

After testing the hypothesis, sort the boats again. Why do you think some of the materials caused the boats to sink?

Experiment #3: What Dissolves in Water?

Some materials dissolve in water, and some do not. Substances that dissolve in water are called soluble, and substances that do not dissolve in water are called non-soluble.

When a substance (the solute) dissolves, it forms a transparent (see-through) liquid called a solution. Your kids will test a variety of substances to determine which ones dissolve and which do not.

Begin by supplying 4 clear cups filled with water for each child or group. Provide a bowl of salt, sugar, flour, and sand.

what dissolves in water experiment for preschoolers

Explain to your kids that some materials dissolve in water and some do not. When a substance dissolves, it kind of looks like it has disappeared, but actually, it has just mixed with the water to make a transparent or see-through liquid that we call a solution.

Today, we are going to test several materials to see if they dissolve in water.

Make Observations

Let your kids look at the materials that you will mix in. Let them feel them and smell them. What do you notice about the materials?

Form Questions

How can we tell if the materials dissolve? Do you think all of the materials will dissolve? Why or why not?

Develop a Hypothesis

Ask kids to predict which materials will dissolve.

Experiment to Test Hypothesis

Help kids add a spoonful of each of the materials to a glass of water. Stir the mixture and then let it sit for a minute or two. What happens? Does the material dissolve?

water experiment for preschoolers about solutions

Save one set of mixtures and let them sit overnight, and examine them the next day. Do you notice any changes?

water experiment for preschoolers to see what dissolves in water

Record, Share, & Discuss Results

Use the recording sheet to record the experiment results.

simple data recording sheet for preschool water experiments

Get the FREE Printables Today

Are you ready to get started on some water experiments for preschoolers?

Preschool Water Experiment Guide

All of the printables pictured here, along with the directions are currently available in my Fun & Easy Experiments with Water guide. Click the button below, complete the form , and I’ll send it directly to your inbox.