## Ten science experiments you can do with a plastic bottle – Part 2

We are back with more bottle science experiments! How did you get on with the first five we shared last week? We have had plenty of feedback from people who tried them out and really enjoyed them so here are five more bottle science experiments to try!

You can find experiments 1 to 5 in this post!

REMEMBER: YOU NEED ADULT SUPERVISION FOR ALL THESE EXPERIMENTS

#### 9. Bottle Rocket Experiment No. 1

This video doesn’t include the science of how it happens, so here it is! As you know from previous experiments… when we mix the vinegar and the bread soda the react rapidly making a salt, water and Carbon Dioxide gas. Gases usually take up more space than liquids or solids so the sudden production of Carbon Dioxide gas causes a rapid increase in pressure inside the bottle. The gas wants to break out of the confined space within the bottle but the cork is in the way. With enough pressure the cork is forced off and the gas escapes.

Newton’s Thirds Law of motion states that…

Every action has an equal and opposite reaction!

This law is what makes the rocket shoot into the air. The first ‘action’ is the cork shooting off the bottom of the bottle; this produces the ‘equal and opposite’ reaction of the bottle rocket shooting off in the opposite direction! It all follows the laws of physics!

#### 10. Bottle Rocket Experiment No. 2

This rockets follows the exact same law as the previous experiment, except this time the pressure is built up by the air we pump into the bottle. This pressure eventually builds up forcing the cork, and the water, out of the bottle and the rocket is then propelled off in the opposite direction, shooting up into the sky.

And there you have it! Ten fantastic experiments to do with a plastic bottle. If you missed the first five you can find them here! Please let us know what you thought of this series and how you got on. If you like these video experiments and would like some more just let us know in the comments below and we will get working on a new series straight away!

ENJOY!

## Fun Friday – how to make an ocean in a bottle

It is a simple and easy Fun Friday experiment today – how to make an ocean in a bottle

All you need for this experiment is…

• an empty clear plastic bottle (a 1 or 2L soft drink bottle will work fine)
• water
• cooking oil (any kind)
• Blue food colouring
• A funnel

What you do…

1. Using the funnel fill the plastic bottle about one third full with water
2. Add a few drops of food colouring to colour the water blue
3. Using the funnel again fill the bottle with the oil (you will notice that the water and oil will quickly settle into two separate layers)
4. Close the lid tightly on the bottle and turn the bottle on its side
5. The water layer will be on the bottom of the bottle
6. If you rock the bottle from side to side you can create a wave like motion of the water, looking just like a little ocean in a bottle; see what kind of waves you can make!

How does it work…

This is a good experiment to explain density. The oil is less dense than the water so it will sit on top of the water, creating two separate layers. The layer of oil keeps the water contained within the bottom half of the water and makes the movement of the water look like waves where the two liquids meet.

I have discussed density in more detail in this previous post as well as sharing lots more density experiments.

If you get bored of your ocean in a bottle, why not stand it upright again and add some Alka Seltzer tablets to instantly turn it into a lava lamp!

Enjoy!