14th March is Einstein's birthday.

To celebrate this fact and to publicise national science week in the UK, I have found some great experiments that kids can do at home.
So gather up your budding professors and get ready for cries of Eureka!

THE SOAP-PROPELLED BOAT – or how to brighten up bath-time

What you’ll need:
• Card
• Scissors
• A baking dish full of water (or you can do it in the bath at home)
• Liquid detergent

What to do:
• Cut out a boat shape from the card. (Make it about 6cm long and 4cm wide)
• Make a notch at the back of the boat.
• Place the boat gently on the water in the dish.
• Pour a little detergent into the notch in the end of the boat.

Your boat should zip across the water…

What's happening?
Water molecules are strongly attracted to each other and stick close together, especially on the surface. This creates a strong but flexible "skin" on the water's surface that we call surface tension. Adding soap disrupts the arrangement of the water molecules and breaks the skin, making the boat go forward.


Custard Gone Crazy

What you’ll need:
• Custard powder (NB not instant custard) / cornflour
• Water
• Bowl
• Spoon
• Eggcup / spoon

What to do:
• Mix 8 eggcups of custard powder or cornflour with 4 eggcups of water, making sure to stir in the water slowly so you don’t get any lumps. (Don’t cook it!)

The result is a strange yellow substance that will either act like a solid - if you punch it quickly, or roll it into a ball OR will act like liquid, if you touch it gently.

If you increase the amounts of custard and powder, you could in theory fill a bathtub with the mixture, and run across the top without falling in. (You’d have to be very quick though!)

What's happening?
The custard powder and water mixture is a mixture of solid particles suspended in a liquid, called a "colloid". When you stir the mix slowly, the custard powder particles can move around in the water quite freely, and so it acts as a liquid. When you stir the mix faster or hold it in your hand tightly, the solid particles rub against each other causing friction. This makes them stick together and act like a solid.

Volcano!

What you’ll need:
• Vinegar
• Baking powder
• Washing up liquid
• Food colouring
• Small plastic bottle
• Balloon
• Plate/tray
• Clay (optional)
• Tablespoon

What to do:
• Put 1 tablespoon of baking powder in the plastic bottle. If you have time make a volcano shape with the clay around the bottle.
• Add a small amount of washing up liquid, and a few drops of food colouring.
• Make sure that the volcano is on the tray / plate.
• Add vinegar and stand well back…

Variation 1: Place a balloon over the end of the bottle and collect the gas – it is heavier than air.

Variation 2: Put a bung in the bottle and watch it fly out.

What's happening?
This experiment demonstrates a classic acid base reaction. Carbon dioxide is given off when the vinegar reacts with the baking powder.

Notes:

National Science Week, UK runs from 10th-19th March 2006. For further information see:
http://www.the-ba.net/the-ba/Events/NationalScienceWeek/

Experiments taken from http://www.planet-science.com/home.html