This past week we did this one. It's called Fireworks in a Jar. It came from "I can Teach My Child". I can't remember if it was a freebie or a purchase.
Materials needed
oil
water
food colouring
plastic fork or stirring implement of some sort
Directions
- Pour warm water in a jar. about 3/4 full
- In a separate bowl mix a few tablespoons (about 3-4) and several drops of food colouring.. same colour or different colour it's up to you.
- Use your stirring implement to gently mix the oil and food colouring together
5. Sit back and watch what happens.
The knowledge behind the experimenting
"the food colouring doesn't like the oil so it's going into the water"
Why do you think that is?
"because we already know that it mixes with water mom. The oil tries to keep it but the food colouring doesn't like to stay with it."
Then I agreed with and explained
Yes, the food colouring dissolves in water not in oil.
The reason it doesn't like the oil is that the oil is less dense than water so it will float on the top. The coloured drops of food colouring are heavier (so more dense) than the oil so they will begin to sink due to the differences in density.