Magic show or science lab?

Sometimes it's hard to tell the difference when chemistry is used in clever ways. Here are 10 videos showing some cool chemistry videos from around the web. Don't forget that some of the chemicals involved can be hazardous if misused. They need adult supervision, and many of the experiments also need protective safety equipment such as goggles, gloves and aprons.

1. The banana hammer

Freezing radically changes the structure of substances. For example, here’s how a quick bath in liquid nitrogen can make a banana as hard as nails....

2. The melting spoon

A classic prank by scientists is to make a teaspoon out of gallium and serve tea to unsuspecting guests. The spoon melts in the hot liquid. In fact it turns to liquid at slightly above room temperature and will melt in the hand. No wonder magicians love it. This video uses a clear liquid so you can see what's happening.

3. The mystery liquid

There are no visual tricks in the following video either - just real science. This is a classic experiment to display chemical kinetics in action. It’s called the “iodine clock reaction” - read more about how it works on Wikipedia.

4. Make fake blood

Movie makers sometimes use dilute aqueous potassium thiocyanate (KSCN) for fake blood. Paint it onto a surface as a colourless solution, then let it come into contact with ferric chloride. The result beats tomato ketchup any time.

5. Thunderstorm in a test tube

It's amazing what you can do with a little bit of sulphuric acid, ethyl alcohol and potassium permanganate. You can even simulate extreme weather conditions in the lab.

6. Elephant toothpaste

What happens when you mix concentrated hydrogen peroxide with soap, and add a pinch of sodium iodide?

7. Pharaoh's serpent snake

Mercury thiocyanate used to be the main component in a firework called the Pharaoh’s Serpent. It’s rarely used nowadays though (the reaction produces toxic gases).

8. Sodium + water + lots more sodium

You might have seen this common lab experiment, in which a small amount of sodium is brought into contact with water. OK, let’s see what happens when you use a much bigger sample of sodium (100g)...

9. Gummy Bear's fiery death

Molten potassium chlorate is a strong oxidizing agent that. It reacts violently with sugar. Gummy Bears are a bit like jelly babies, and have a high sugar content...

10. Make a fire extinguisher

After all those explosions, here’s how to put OUT fires instead of lighting them. It uses ordinary kitchen ingredients (bicarbonate of soda and vinegar) to create an invisible gas to blow out a candle. Remember: if you’re doing this at home, don't let children handle matches or candles, and don't leave lit candles unattended.