Exploding soap bubbles

Soap bubbles containing a mixture of oxygen and methane can be used to produce spectacular explosions and impressive shock-waves that will always please

Special tips:

• practise the experiment before attempting with a class, practise makes perfect with regards to mixing the gases in the correct proportions
• start with bubbles of pure methane to illustrate the slow combustion of methane in the limited supply of oxygen from the surrounding air
• if the bubbles are not exploding or just burning with a yellow flame, adjust mixture until successful
• once confident in the procedure, try igniting similar quantities of the bubbles held directly on your hand