When I saw that the theme for the latest Get Crafty was water based crafts, I immediately thought of this. Even though it doesn’t use water and it isn’t even really a craft, it is lots of fun so I’m going to pretend it is a water craft anyway 😉
The Fun Bit….
All you need to make an explosion like ours is a large bottle of Diet Coke (you can use other fizzy pop, but Diet Coke has the best results) and a packet of mint flavoured Mentos.
- Place the opened bottle of Diet Coke on a flat surface outside away from anything you don’t want to get wet.
- Make sure all little people are stood WELL back, you should also wear safety goggles of you have them although we don’t so we didn’t..
- Open the Packet of Mentos down the side but keep them all in the packet still.
- When you’re ready, slide the Mentos’ into the bottle.
The Science Bit….
Scientists believe that the main cause of Coke & Mentos explosions is a physical reaction and not a chemical reaction as they previously though. The process that leads to the explosion is called nucleation.
Basically, the carbon dioxide in the Diet Coke (all the fizzy bubbles) is looking for a way to get out which means it’s drawn to anything that it can grab on to. It’s particularly attracted to Mentos because the surface of each mentos is sprayed with 40 microscopic layers of liquid sugar it’s covered with lots of tiny bumps, each called a nucleation site. The carbon dioxide grabs on to each nucleation site and begins to release bubbles and because there are so many tiny bumps on the surface of a Mentos, an incredible number of bubbles will form around each Mentos when you drop it into a bottle of soda.
Since the Mentos are also heavy enough to sink, they react with the soda all the way to the bottom of the bottle, the escaping bubbles quickly turn into foam and the pressure builds inside the bottle, which leads to the explosion.