Question: How do would make you make a really cool explosion but not too big?

Sinead Loughran answered on 11 Nov 2016:

When I was a student scientist we used to make rockets out of water bottles and ‘dry ice’.

When we received frozen items, they came packed in ‘dry ice’. Dry Ice is the common name for solid carbon dioxide (CO2). It gets this name because it does not melt into a liquid when heated; instead, it changes directly into a gas. That’s what makes it pretty useful as a rocket launcher.

Check out this video to see what I mean;

You could make a similar (but less explosive) rocket with baking soda and vinegar in a water bottle .