Make a Simple Electromagnet
Make a magnet that turns on and off with electricitySuitable for kids aged 6+CAUTION
- Do not hold the wire on the battery for long periods without removing it. The wire and/or the battery terminal may get hot.
- The nail is sharp, handle with care.
What to do:
- Large nail
- Plastic coated wire (stripped of the plastic at each end)
- Washer or paper clip (any metal object containing iron will work)
- Wind the plastic coated wire tightly around the nail about 40 times - more turns makes a stronger magnet. It doesn't matter if the wire turns overlap.
- Hold one end of the stripped wire to one end of the battery (terminal), and the other end of the stripped wire to the other battery terminal.
- With the wire connected to the battery, pick up your metal object (washer or paper clip) with the sharp end of your new electromagnet.
- To turn off the magnetism, break the circuit by removing the wire from the end of the battery.
- Can you think of a way to hold the wires onto the battery without using your fingers - masking tape and paper clips might get you started?
- As a further project you might like to use things around your house to design a base and mount to hold the nail and battery in place. Make sure you get your parents to help.
Why is it so?Magnetism and electricity are closely related. When the electric current flows near the nail, all the mixed up magnetic domains in the steel nail line up like little soldiers and point in the same direction. The magnetism in the lined up domains adds-up to make a strong magnetic field. When the electricity stops flowing the domains go back to pointing in random directions and the magnetism is lost. Electromagnets are used in real life all the time, in 'tube-type' televisions, in loudspeakers, in some door bells and in scrap metal yards.
Attract matchsticks using a magnet and leave your friends guessing!Suitable for kids aged 8+ with adult supervisionYou Need:
What to do:
- Matchsticks (non-safety or 'strike anywhere' matches with the red head. work best).
- A strong neodemium magnet.
- Open up a matchbox and select a number of matches.
- Place the neodemium magnet onto the heads (red) of the matchsticks.
- You'll observe that they do not attract or move towards the magnet.
- Burn the matches by striking them as normal, once head of match is burned you can extinguish it by blowing air onto it.
- Now repeat step 2 and place the magnet onto the matchstick heads, you should observe that they're attracted to the magnet! But how?
Why is it so?The red matchstick head is made from iron oxide and under normal circumstances it is not magnetic. So that's why you would of observed the unused/fresh matchstick not sticking (attracting) to the magnet. But when the matchstick is struck and burnt, it produces pure iron, which is magnetic.
A simple equation for the reaction would be:
Iron(III) oxide + carbon → iron + carbon dioxide
SO when the matchstick is burnt, it undergoes a chemical reaction, turning the red head (iron oxide and carbon) into iron and carbon dioxide gas. The iron produced is what causes the matchstick head to attract to the magnet. This trick is more than a magic illusion... it's SCIENCE!