This week, your kit is full of experiments all to do with magnets and magnetism! Did you know? Some things are magnetic, but not everything that is magnetic is a magnet! Here’s Chemical Cress to explain why (her magnet isn’t as colourful as yours!): [embedyt] https://www.youtube.com/watch?v=Oi2nUFkdHng[/embedyt]   In your kit you should have:

• Iron filings
• Paperclips
• 1 magnet
• 1 strip of magnetic tape
• Robot templates

You will need:

• Scissors (ask a grown-up)
• Some 1p and 2p coins
• *Optional* A small pot with a lid

Making a Temporary Magnet

The magnet that you recieved in your kit is called a permanent magnet, because it never stops being a magnet. You are going to make something called a temporary magnet, which means that it can be a magnet for a little while, but it won’t be a magnet forever.

• Take your permanent magnet and a paperclip.
• Rub your magnet up and down the paperclip 50 times to “charge” it.
• Put the magnet to one side and try and pick up another paperclip using the one you just “charged” by touching it gently as pictured.
• If it doesn’t pick it all the way up, try rubbing your magnet on the paperclip again, making sure to rub it on both sides of the paperclip.
• Remember – it won’t work as a magnet forever so you may need to recharge it.

Here’s Chemical Cress to explain how you turned something that is magnetic, into a temporary magnet – [embedyt] https://www.youtube.com/watch?v=ouyUizMXto0[/embedyt]  

Magnetic Coins

For this experiment you will need some coins and your magnet. If you can, use a selection of older and newer coins, and a mix of ‘copper’ and ‘silver’ coins.

• Use your magnet to try and pick up the coins. You should notice that you can pick up some, but not others, even if they are the same value of coin!

Why is this? It’s all to do with what they are made out of. The ‘copper’ 1p and 2p coins were traditionally made from a bronze alloy of copper, tin and zinc. However, since September 1992 they have been made from copper-plated steel. Steel is magnetic so copper coins newer than 1992 will be magnetic but older coins are not. Since January 2012, the ‘silver’ 5p and 10p coins have been made from a nickel-plated steel, in turn making them magnetic because both steel and nickel are magnetic. Did you find any non-magnetic coins? 20ps and 50ps are made of an alloy of 75% copper and 25% nickel. Nickel is magnetic but copper is not and there is not enough nickel in a 20p or 50p to make them magnetic. This is what 5p and 10p coins used to be made out of. Maybe one day our 20ps and 50ps will change too! Watch this video to find out which metals are actually magnetic. [embedyt] https://www.youtube.com/watch?v=RisBgJNpZq0[/embedyt]

Finding a Magnetic Field

A ‘magnetic field’ is the space around the magnet that is affected by the magnet. Magnetism is a non-contact force which means it can move things that are close to it, even if it isn’t fully touching them.

• Grab your bag of iron filings but keep them in the bag. Keep the bag closed.
• Put your magnet on the outside of the bag and move it around until the magnetic force picks up some iron filings. It works, even through the bag!

Can you see they form a pattern that looks a bit like a hedgehog’s spines? This is the magnetic field! You should either keep your iron filings in their bag or tip them into a little pot that has a lid. Never touch your magnet directly onto the iron filings because they will be really difficult to get off! If you do accidentally touch your iron filings with your finger, make sure you wash your hands straight away so that you don’t accidentally get them in your eye because they will really hurt!

Changeable Fridge Magnet

We know that magnetic things aren’t always magnets, but magnets are always magnetic so they can stick to each other! In this activity you are going to make a fridge magnet that you can change by sticking another layer on top! In your kit you have 2 robots. You don’t have to use these, you can draw your own character like a person with different clothes to wear, or a car with different wheels, if you would prefer.

• Cut out your robot heads, bodies and legs (keep the legs as 1 piece, not 2 separate legs). So now you should have 2 heads, 2 bodies and 2 pairs of legs!
• If you want to colour in your robots, or make you own design, do this now.
• Cut your magnetic strip into 6 pieces. Peel off the orange plastic from 1 side and stick a piece to the back of each part of your robots. Try and stick them in the middle of each piece so they will line up nicely when you stick them together.
• “Build” a robot on the fridge. Try changing it’s head by sticking the other one on top!

The magnetic force is strong enough to go through the paper and still stick the magnets together.