Making rain experiment

By Jennifer Francey

Contents Required1 x Large deep round bowl1 x Small Square bowl3 x CoinsTable SaltFood ColouringTray of iceCling filmScissorsHot waterKitchen roll for cleaning up

Step 1The first step of the experiment was to fill the bottom of a large mixing bowl with hot water. The water is used as a representation of the sea as we have here on earth.

Sea water in Tahiti

Step 2The next step was to add some food colouring to the water to make it look even more like sea water. This would also help with the experiment to show the difference between our sea water and the rain water collected should the experiment be successful.The food colouring used, belonged to my Nannies father, my Great Granddadwho unfortunately I never met, but it means the colouring may be 50+ years old at least.

Step 3Again the addition of some table salt ensures the sea waters authenticity as well as providing us with a difference between the sea and rain water.

Harvesting sea salt

Step 4Next, I placed a square bowl in the centre of my larger bowl. This was to be used as my collection bowl for the rain water that fell.

Step 5Using cling film and stretching it tightly across the top of my bowl, I created a tight seal ensuring that none of the warm air rising could escape.Planet earth has an atmosphere and an ozone layer. Like the cling film used here, earths atmosphere creates a barrier from solar flairs and acts as a ceiling containing our clouds which are formed when warm air rising meets the colder upper atmosphere.

Step 6 Using plenty of ice and placing it on top of the cling film, we created the colder upper atmosphere. By doing this, it gives a visible contact area between the warm and cold layers and we can then see the water forming on the underside of the cling film. In the natural world this can‘t usually be seen as it happens up in the clouds. Clouds are formed when warm air coming off the land or sea rises and meets the cooler air from either of the two poles or the cold upper air in our atmosphere.

Step 7The melt down!! From the close up photograph we can clearly see how water (rain) droplets have started to form to the underside of the cling film.

Step 8After some 45 minutes we have totally melted the ice and again water (rain) droplets can be seen on the underside of the cling film. The coins help to centralise the rain droplets into our smaller bowl. This is pretty much what happens in the clouds above us!! The water droplets slowly get larger and larger until the cloud can no longer support their weight and this is when the water starts to fall from the cloud which we call rain.

Step 9It’s raining…..Not the clearest of pictures, but we can see a drop of rain water just about to fall as it gets too heavy to be supported.

Step 10The results are in!!!After carefully removing all the melted ice from on top of the cling film along with the coins, I then took off the cling film to see how much rain water had been collected. In total I left the experiment for 45 minutes to an hour until all my ice had melted , this gave more reaction time between the hot and cold temperatures and gave me more rain fall the results of which can be seen in the corner of my yellow bowl.