WHAT YOU NEED:
- 1 clear plastic bottle
- Jug of water
- Vegetable oil
- Food colouring
- An effervescent tablet – must contain
citric acid and sodium bicarbonate
WHAT TO DO:
1. Pour vegetable oil into your bottle
until it’s about ¾ full.Use your jug of
water to top up the last bit with water.The water will sink to the bottom of the bottle and the oil will float
on the layer of water.
2. Add a few drops of food colouring – it
will take a few moments to sink through the oil before it mixes with the water.
3. Break your effervescent tablet in half
and drop the two halves into the bottle.
4. Loosely place your bottle lid back on
the top of the bottle and watch your bottle full of colourful bubbles!
The Extreme Science behind this:
Water is heavier than oil, which is why it
sits at the bottom of the bottle.When
the effervescent tablets are dropped in bottle and hit the water and start to
dissolve, they begin to fizz.The
fizzing is bubbles of carbon dioxide gas which begin to rise through the
bottle.The bubbles attach themselves to
little blobs of water which they carry up with them to the top of the
bottle.When the bubbles reach the
surface, they pop, so without a bubble to keep them floating, the little blobs
of water sink back down to the bottom.