Liquid of life

Activity overview

Run the activity

This activity has been co-created with the Eden Project as part of Explorify’s collaboration with Science and Discovery Centres.

1. You’re going to watch a short video. The aim isn't to find right answers, it's to explore ideas and find out what they know.

• Do they know what might happen based on the image?

2. After you've watched the video, lead a discussion with your class:

• What do you think it’s like inside the big dome you saw at the start?
• Where do you see water flowing in the film?
• Where do you see water evaporating?
• Where do you see water condensing?
• How does the water behave on the leaf at the end?
• Ask the class to describe what they saw using only one word.

Background science

Water can seem unremarkable.  We drink it; wash our bodies, clothes, and cars with it; swim in it; and we shelter from it when it falls as rain, hail, or snow.  Our bodies are 60% water, the planet’s 70% water.  In a glass, water appears colourless and without taste or smell.  Yet, if there was no water, there would be no life on Earth.  Water is the only substance found on the planet in all three states - liquid, solid and gas – at naturally-occurring temperatures.  That’s why we have a water cycle: the change in state is driven by changing temperatures.

Look closely and you will see the effect of water vapour rising from the tree canopy (clouds of condensing water droplets).  There’s also a ‘cloud bridge’ at Eden where evaporation is more easily spotted.  The warmer the temperature, the faster that water evaporates.  When the vapour – gas – meets a colder temperature, it condenses.  You can also see this happening on the hexagonal plastic panels inside the domes.

A river of liquid water tumbles through the forest, and rainwater streams from the roof of a shelter.  Both are artificially created.  Earth itself has so much surface water that, seen from space, it appears blue. Nearly all the water on the planet (97%) is salt water; most of the fresh water is frozen at the polar ice caps so only 1% of Earth’s water is available to us as liquid. 

Eden’s Rainforest Biome is so warm, you won’t find ice there unless you bring some in your water bottle.  Solid water – ice – is unique because it floats on top of its liquid form: water.  Ice is less dense, and it’s because of this and the oxygen trapped beneath, that life survives under frozen seas.  The layer of ice actually insulates the water underneath.

The film ends by showing, in slow motion, droplets of water rolling on the surface of a taro leaf.  Taro leaves are hydrophobic (water-repelling), so water does not wet the leaf.  There’s an abundance of water in a rainforest.  When you see water droplets on glass table-tops or taro leaves, they clump together and form dome-like shapes.  The molecules in the water like to stick together. 

Watch out for...

Children may think that plants take in water through their leaves rather than through their roots. 

They may not realise that the plants at Eden are growing indoors, inside a giant greenhouse, and, therefore, the rain we see in the film is artificial; it isn’t falling from the clouds.  The Eden Project does, however, harvest rainwater in a big way, to water the plants and even flush the visitor toilets.  When it was first built, in an enormous clay pit, engineers had to solve the problem of flooding at the site.  They did this by storing and using the rainwater.

Also watch out for the common misconception that water needs to boil in order to produce vapour.  Evaporation occurs at any temperature above freezing point, 0°C.

This does not need to be corrected during the session, but you can pick it up later.

Take it further

Activities

Find out how to make a water cycle model here.

A plan for a water cycle fortune teller can be found here.

Try adding droplets to an already-full glass of water in this experiment.  Or you could see if paper clips will float or experiment with water droplets placed on wax paper.

In this experiment, children find out how water in its solid state is less dense than water in its liquid state.

Learn how to save water at home and school with these tips from the Eden Project.

Or you could take an exciting virtual tour of the Eden Project here.

If you are in the area, consider visiting Eden for an educational experience that will connect your pupils with nature in an immersive and unforgettable way.

Linked Explorify activities - our recommendations:

What’s Going On?  Wet, and not so wet, leaves  Watch how a variety of leaves repel or channel away rainwater.

Problem Solvers  Make a plant self-watering device  A Climate Challenge activity which underscores how all living things need water to survive.

Odd One Out  Where is the water?  Three images of water condensing in different ways.

Problem Solvers  Water carriers  Can your class create a water carrier that will not leak from junk materials?

What’s Going On?  Sensitive plant  Watch a plant with leaves that move when its touched.

What if an astronaut gets thirsty?  How water is recycled on the International Space Station.

Watch

Here’s a BBC video explaining the water cycle.

Cross-curricular

Children could research and make a presentation explaining the water cycle. This could be interactive using PowerPoint or Google Slides on a laptop, acting in groups, or a piece of writing. This NASA page will help the children.  

Research how flooding has devastating effects of people’s lives around the world then design and build a flood-proof house with this Practical Action activity.