condensation | Kelly St. Scientists

Well after our success with making a cloud we just had to think about why some clouds rained and why others didn’t?

So we conducted an experiment to investigate this.

We hypothesised it was about the quantity of water the cloud had soaked up, and recorded these in our science logbook.

Daniel recorded that he predicted clouds needed more water to make rain.

Alex predicted that the cloud with less water would make rain.

So we set up our experiment….

We started with a tub of plain water to represent the air.

We squirted shaving foam on top to be the cloud.

The foam floated on top of the water, like a cloud hanging in the sky.

We used dropper s to pick up and drop blue food colouring onto the foam.

We used blue colouring to pretend it was water in the clouds. The dye meant we could see what happened to it. We added a tiny bit to one and a lot more to another.

We looked closely through the magnifying glasses.

We talked about what we thought was happening. One cloud had made rain!

We looked again. Daniel and Alex added more dye to see what would happen.

The clouds with lots of dye ‘water’ rained for a while.

We recorded our findings in our logbook.

Natalie recorded that the large cloud stayed the same when the little cloud let rain through

Rebekah recorded the rain falling from the cloud.

So clouds with lots of water are the ones that make rain. If a cloud only has a little water, it doesn’t. Lots of water is heavier than a little water so the water falls down when there is enough in the cloud to be heavy, but big clouds need more water to become too heavy and rain.

But we didn’t stop there. Chloe and Amelia wanted to see if they could speed things up by mixing the cloud (foam) and (water) air.

Investigating best stirring implement – glue spreader or paint brush?

“I’m going to make mine sparkly like Elsa”.

That got us thinking about potions and mixing – what could we add to what? Would different things happen? Hmmmm.

But the weather had changed! It had rained, so that led us to think about where the rain comes from?

Chloe: “The clouds – it falls out the clouds.”

The rain made puddles, and came from the clouds but how did it get into the clouds?

So a cloud is made of water that has evaporated (turned into a gas)from a source of water like a puddle or river or sea.Then it has gotten cold again and condensed (turned back into tiny wee water droplets) sticking onto miniscule bits of dirty air.

You can make a cloud too!

All you need is: