Experiment 7: Black Snakes!

The Experiment

The Results

I'd give it a B-.  We had a couple of goes, but couldn't quite get the snake effect to work as we wanted, but we still enjoyed doing it.  If it was anything, it was closer to a Black Octopus than a Snake.

The Science

I'm just going to link to this page.  I didn't do much chemistry at school so I don't really understand the reaction myself.  Suffice to say that the bicarb and the sugar release CO2 gas which puffs up the ashy residue into a snake.

Experiment 6: Water Rocket!

The Experiment

The Results

A pretty neat rocket, it fired up quite high. We were also able to keep re-using it, which added to the fun.

The Science

This, of course, is Newton's Third Law of Motion in action: commonly phrased as "for every action there is an equal and opposite reaction".  Essentially the when the bung pops out, the compressed air trapped in the bottle is free to expand and forces the water out towards the ground, which in turn results in the rocket being propelled upwards.

Experiment 5: Lava Lamp!

The Experiment

The Results

Cloudy water.  Then after a re-jig, slightly less cloudy water.  This did not go well.  But that's all part of science too.  We learn from our failures as well as our successes.

The Science

Apparently what's supposed to happen is the salt falls through the oil, takes a bit of food colouring and oil with it and then dissolves in the water, releasing the oil to float back to the surface and leaving a puff of colour.  

Experiment 4: Elephant Toothpaste!

The Experiment

The Results

A nice gush of pink foam.

How To Make Elephant Toothpaste

1. Put on your science goggles, science gloves and science coat.  Hydrogen Peroxide is a bleaching agent, so cover up!
2. Mix 100 ml of Hydrogen Peroxide 6%, a tablespoon of washing-up liquid and some food colouring into a bottle.
3. Mix 1 tablespoon of Dry Yeast and 3 tablespoons of warm water in a jug and allow to stand for 30 seconds or so.
4. Remove any lumpy bits from the yeast solution.
5. Pour the remaining yeasty liquid into the bottle.
6. Enjoy!

The Science

The yeast acts as a catalyst breaking down the Hydrogen Peroxide and releasing the Oxygen.  The washing-up liquid in the water traps the Oxygen creating bubbles.

Experiment 3: Teabag Rockets!

The Experiment

The Results

This one didn't quite go according to plan.  Further viewing on the Interweb has shown that everyone else seems to do it inside.  Maybe the draft or the cold weather affected it.

The Science

The principle is similar to a hot air balloon.  The burning top of the cylinder of paper heats the air, which rises up allowing the denser, cooler air to push in from the bottom.  This convection current allows the lightweight ashy residue of the bag to fly into the air.

Experiment 2: Slime!

Making Slime!The Experiment

The Science

The glue is a liquid polymer (polyvinyl acetate) adding the Sodium Tetraborate causes the PVA molecules to link together forming one large rubbery polymer.

Experiment 1: Make a Volcano!

Milk Make a Volcano

Here, Phoebe explains what we're going to do.

How To Make a Volcano

1. Take one plastic volcano.
2. Fill approx 2/3 full with vinegar
3. Add a teaspoon of Sodium Hydrogen Carbonate
4. Quickly replace the lid
5. Enjoy

Memorable Quotes

While spraying the ground with the hose to clean up the foam, she excitedly exclaimed "Look!  I'm washing science off the patio!"

The Science

The full explanation can be found here, but the main thing is this: the baking soda (sodium hydrogen carbonate) and vinegar (acetic acid) react to produce carbon dioxide gas.  This escapes from the solution as bubbles, pressurising the volcano and spraying out of the hole in the top.