7 Eco-Friendly Science Week Experiments for Children

Science Week is a time to embrace the beakers, break out the lab coat and give some experiments a go! To help inspire your child, check out our fun (and sustainable) science experiments that’ll get your toddler’s brains buzzing.

Every August, schools, universities, libraries, and museums around the country join for a week to celebrate all things STEM (science, technology, engineering, and mathematics). But science isn’t just for labs and classrooms. Rather, it can start at home or in early learning environments through simple, playful discovery.

That’s why science week experiments are such a powerful way to engage young children. Through simple activities, toddlers can explore big ideas like gravity, magnetism, light and chemical reactions in a safe and exciting way. Even better, science week experiments for toddlers don’t require complicated equipment. With everyday household items and a little curiosity, you can turn an ordinary afternoon into a fun, hands-on learning experience that encourages creativity, observation and early STEM skills.

This year’s theme, Seeds of science: Nurturing knowledge for all, celebrates the problem-solvers of tomorrow and respecting and protecting our planet. And it all begins with small moments of curiosity today.

Discover more: A guide to nature-based learning

Moreover, Science Week is the perfect time to spark children’s curiosity through eco-friendly science experiments. By using sustainable materials, you can inspire your child’s scientific curiosity while also introducing them to conservation and sustainable practises.

Simple Science Week Experiments for Toddlers

Toddlers learn best when they can touch, explore and experiment through play. Hands-on learning encourages children to ask questions, notice patterns and develop early problem-solving skills. All of which are at the heart of our Learning for Life curriculum and is further developed through our Enrichment Program.

These science week experiments for toddlers are designed to be simple, safe and engaging for young children. Using everyday materials, each activity introduces basic scientific ideas while still feeling like play.

Discover more: The Benefits of Imagination Play

Whether you’re at home or in an early learning setting, these science week experiments help build curiosity, creativity and a love of discovery from an early age.

1. Dancing Sultanas

This experiment looks like magic, but it’s actually science in action.

What You’ll Need:

• A glass
• Sparkling water
• Sultanas

How to guide:

Fill a clear glass with sparkling water and gently drop a few sultanas inside. At first, they’ll sink to the bottom, but soon bubbles will begin to cling to their surface. As the bubbles build up, the sultanas rise to the top before falling back down again, creating a fun “dancing” effect.

This activity demonstrates how density changes depending on an object’s environment. The sultanas are initially denser than the water, causing them to sink. When bubbles attach to them, their overall density decreases and they float upwards.

Even better, it’s completely waste-free. Once the experiment is finished, you can simply enjoy the sparkling water and sultanas.

2. Upcycled Rainbow Spinners

For any parents still yet to clear out their boxes of old CDs, this is the science week experiment for you! Rather than leaving them to collect more dust in the cupboard, you and your child can help turn them into colourful science tools.

What You’ll Need:

• Old CDs
• Scissors
• Power drill (adult supervision required)
• Twine

How to guide:

Cut the CDs into small shapes and carefully drill a small hole in each piece. Then thread twine through the hole and hang the pieces near a window.

As sunlight hits the reflective surface, the CDs scatter light into rainbow colours across the room. This simple activity introduces children to the concepts of light reflection and refraction, while also encouraging creative thinking and sustainability through upcycling.

3. Lemon Juice Invisible Ink

This classic experiment turns secret messages into a science lesson.

What You’ll Need:

• Fresh Lemon or lemon juice
• Bowl
• Paper
• Paintbrush
• Hairdryer or light bulb

How to guide:

Start by squeezing half a lemon into a bowl (or using store-bought lemon juice). Invite your child to dip a paintbrush into the juice and write a message or draw a picture on paper.

Once the paper dries, the writing becomes invisible. When gently heated with a hairdryer or held near a light bulb, the hidden message slowly appears.

The reason? Lemon juice contains acids that oxidise when heated, causing the writing to turn brown and become visible.

4. DIY Compass

Magnetism can feel like magic to young children and this experiment brings it to life.

What You’ll Need:

• Small cork
• Bowl
• Water
• Steel needle
• Bar magnet

How to Guide:

Start by stroking a steel needle with one end of a bar magnet around 20–30 times in the same direction. This magnetises the needle.

Next, float a cork in a bowl of water and place the needle on top. As the cork spins, the needle will align itself north to south, just like a real compass.

It’s a fascinating way for children to explore how magnets interact with the Earth’s magnetic field.

5. Paper Mâché Volcano

Few science activities are as iconic as the erupting volcano.

What You’ll Need:

• Recycled newspaper or scrap paper
• Foil
• Flour
• Water
• Plastic bottle
• Cardboard base
• Non-toxic paint
• Baking soda
• Vinegar
• Optional: food colouring

How to Guide:

Start by taping a clean plastic bottle onto a cardboard base. Build the shape of your volcano using scrunched-up foil, then cover it with paper mâché made from flour, water and recycled newspaper strips.

Once it dries, let your child decorate the volcano with paint.

When you’re ready to erupt, add a few teaspoons of baking soda, a splash of vinegar and a few drops of food colouring. The fizzing eruption demonstrates a chemical reaction between the two ingredients.

6. Ocean-in-a-Jar Ecosystem

This calming experiment introduces children to ecosystems and sustainability.

What You’ll Need:

• Glass jar
• Water (rainwater works well)
• Sand or small pebbles
• Aquatic plants or seaweed
• Small marine toy

How to Guide:

Fill a clear glass jar with water, leaving about an inch of space at the top. Add a small layer of sand or pebbles to create the ocean floor, then include aquatic plants or seaweed and a tiny marine figurine.

Place the jar near a window with indirect sunlight. Over time, the plants release oxygen while water evaporates and condenses along the glass, demonstrating how natural ecosystems balance themselves.

It’s a wonderful visual way to talk about ocean health and environmental responsibility.

7. Sustainable Water Filtration

This simple experiment helps toddlers understand the importance of clean water.

What You’ll Need:

• Recycled plastic bottle
• Clear jar
• Scissors
• Water
• Soil
• Sand, gravel or charcoal

Start by mixing soil into a container of water to create “polluted” water. Cut a plastic bottle in half and poke a hole in the lid. Turn the top half upside down into a jar to create a funnel.

Layer sand, gravel or charcoal inside the bottle to create a natural filtration system. When you pour the dirty water through the filter, the layers help remove many visible particles.

Although the water may look cleaner, remind children that it still isn’t safe to drink. Instead, reuse it for watering plants.

What Are the Benefits of Science Experiments for Children?

Eco-friendly science activities provide more than just a fun afternoon. They support important areas of early childhood development while introducing children to environmental responsibility.

Some of the key benefits include:

• Encourages curiosity and exploration as children ask questions about how things work
• Supports early STEM learning by introducing basic science concepts in a playful way
• Helping toddlers develop observation skills as they watch reactions and changes
• Builds creativity and imagination through hands-on experimentation
• Encourages learning through play, which is essential in early childhood development

Science Week is also a reminder of the importance of nurturing future innovators. Australia’s Minister for Industry and Science, Tim Ayres, emphasised how vital STEM education is for the future during following Science Week 2025.

“National Science Week is an opportunity for all Australians to meet real-life scientists, dive deeper into hot topics and celebrate the cultural and economic impact science has on our society.”

Today’s curious toddlers could very well become tomorrow’s scientists, inventors and environmental leaders.

Discover the Joy of Science at Explorers

At Explorers Early Learning, curiosity, discovery and play-based learning are at the heart of everything we do. You can also explore more about our learning philosophy and programs on our website, including our kindergarten programs, Reggio Emilia inspired curriculum and much more.

To experience it for yourself, book a tour at one of our Explorers Early Learning centres or inquire today.

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