A Prediction Experiment

Round and Round the Water Goes

The rain that falls today is the same water that has been used over and over for billions of years. Today you'll learn how water travels in a never-ending circle, then you will predict each step.

Before we start — where do you think a puddle actually goes when it dries up in the sun?

Water changes form

Water can be a liquid (the sea, a puddle), an invisible gas called water vapour, and a solid (ice). Adding or removing heat changes it from one to another — and that's what drives the whole cycle.

Quick check, together: When water turns into an invisible gas in the air, what is that gas called?

Answer: Water vapour — water as an invisible gas.

Three big steps

Evaporation: the Sun heats water so it rises as vapour. Condensation: high up it cools and turns back into droplets, making clouds. Precipitation: the droplets grow heavy and fall as rain or snow.

Quick check, together: What is the name for water falling from clouds as rain or snow?

Answer: Precipitation (rain, snow, sleet, or hail).

A circle with no end

The rain that falls flows back to rivers, lakes, and the sea (collection) — where it can evaporate again. The same water goes round and round forever. No new water is made and none is lost — it's just recycled.

Quick check, together: Is brand-new water made each time it rains, or is the same water reused?

Answer: The same water is reused — recycled around the cycle, never created or destroyed.

What did the cycle teach us?

The same water, used again and again — round and round forever.