My family like to do Science experiments, but we've tried so many elaborate ones that haven't worked, that "Mum's Science flops" have become a household tradition. However, we find some good, simple ones from time to time that I really like. These are in the category that if we can manage them, anyone can, and their results are quite effective.

1) Potato Slices.

Fill one cereal bowl with fresh water and another with very salty water. Place a potato slice in each bowl and leave to stand for several hours. Take the slices out and compare them. You'll find the salt water slice has withered and shrunk. This is because the cell walls of the potato allow plain water to pass in and out freely but do not allow the salty water in. The potato slice in the salty water shrinks because liquid leaving the potato cannot be replaced.

2) Psychedelic Milk.

This one is great. Pour some milk into a breakfast bowl, drip in a few drops of four different coloured food colourings (or at least more than one) then add one or drops of dishwashing detergent. Watch carefully for several minutes.

The surface of the milk has a sort of skin called surface tension which is broken when detergent is added, causing the milk to swirl around. Adding colour allows us to see it happen.

3) The bouncing raison.

Drop one raison into a glass of fresh lemonade (it can't be flat). It will sink, and then when it gets to the bottom it will rise again. Then it will sink and then it will rise and so on. Looks really weird.

The raison rises when bubbles form on it because the bubbles float to the surface dragging the raison with them but at the top they burst. The raison is now heavier than water and sinks to the bottom again where more bubbles form on it which ..... and so on until there's no fizz left in the drink.