If you want to do your own Diet Coke and Mentos experiment, then you will need some kind of mechanism to allow you to release the mentos into the Coke from a safe distance.

You could probably cobble something together yourself, but one thing that you can buy is the Geyser Tube, which is available from gadget stores such as Firebox for about a fiver.

Put the mentos in the tube, then pull the string and stand back. The pin will pull out and release the mints into the Coke.

Try this as part of a Sc1 investigation – test different brands of cola, types of fizzy drink etc.