The shaving cream rain cloud is a great little experiment, that takes no time at all to set up. It’s a simple way to teach kids about clouds and rain, and is great for all ages, even as young as our 2 year old. It also makes for a great invitation to play!
A great way to start this experiment is to take your kids outside to look at the clouds. Talk about the shapes of them and talk about the different colours and sizes they are. You could discuss how some days they are light and wispy and other days they are heavy-looking and dark grey.
When you’re setting up the experiment you can talk about how the shaving cream is acting like a cloud and the food colouring is all the water building up in the cloud. When the shaving cream is fill the coloured water starts to fall through the shaving cream. Just like when a cloud becomes heavy with water it starts to fall as rain.
If you have older kids you might like to tell them that clouds are a large collection of very tiny molecules of water, and ice crystals, that have risen up into the sky from the process of evaporation. These droplets are so small and light that they can float in the air.
To become rain, the water condensing in the clouds has to become heavy enough to fall back to Earth. The tiny droplets just aren’t heavy enough to fall by themselves.
For the rain to become heavier, the droplets need to grow. They do this inside the clouds by acquiring more water and becoming larger. All the cloud droplets will collide with one another and become larger.
In the right clouds, this process will be happening to millions of tiny droplets, all growing at the same time, but at different speeds.
Eventually, if the droplets keep growing, they become so heavy they can’t stay floating in the cloud any longer, and the droplets will start to fall as rain.
Of course, once the water has fallen to earth, it’s eventually reheated and evaporates as tiny water molecules up into the air, to begin the process.
Shaving cream rain cloud experiment
You will need
A glass jar or jug
Containers for your food colouring
What to do
1. Have you or your child fill a glass jar, or jug, up to about 3/4 fill.
2. Fill the rest of the jar with shaving cream.
3. In seperate smaller containers, mix up some food colouring with water.
4. Use the eye droppers to drop the food colouring onto the shaving cream.
5. Watch how the coloured water starts to drip through and make interesting patterns in the container below.
It pays to drop just a few drips of food colouring at a time, and wait for the process (remember your ‘clouds’ are filling up with water), slowly the coloured water will make it’s way through the shaving cream.
Drops placed in the centre of the shaving cream will move more slowly, and drops at the edges will work through more quickly.
Eventually the water will go a murky purple colour, so it pays to take your time with this experiment.
And, finally, this can be quite a messy project if you have little ones, so have a towel or 2 to hand!