Conductors and insulators!

Electric fences often stop animals going where they shouldn’t… unfortunately, Brainiacs are known to roam far and wide. The Brainiacs have been finding out to their cost why conductors and insulators are so important when it comes to a shock from an electric fence. Challenge your class to recognise good conductors and insulators… without the danger that our Brainiacs are trained for!

What you’ll need

  • A battery pack
  • A bulb
  • Wires
  • A range of objects to try out in your circuit. (Metal spoons, tin foil, a Wellington boot and more)

If you’re not confident with your circuits you can pick up a ‘human conductivity stick’ fairly cheaply that will help you use your pupils as a circuit!

How to do the experiment

Using a simple circuit like a battery and a bulb, make a gap in your circuit. Set out a range of objects for the class to categorise into conductors and insulators. Try your objects in the gap to see if they let electricity pass through them easily or not.

The conductors will make the light come on and the insulators won’t.

Finished already?!
If you have any eager beavers in your class then challenge them further by getting them to list the properties of the conductors and the insulators. Get them to write the name of the object, whether it is a conductor or insulator and then two describing words about the object (smooth, soft, shiny, rough etc.)

Why does it work?

Everything around us is made up of atoms. These atoms have particles called ‘electrons’ in them. In some materials, those electrons can be moved from one atom to the next like a game of pass the parcel. The atoms of some materials don’t like this game so they like to cling on to their electrons. Materials that like to play ‘pass the electrons’ make good conductors; such as metals. Those that don’t like to play this game make good insulators; such as polystyrene.

Did you know?

While your home uses 240 volts from your plug sockets, the circuit needed to get all that power from the power station to your house uses up to three-quarters of a million volts in certain sections of it... but that’s nothing to a bolt of lightning which can be up to a billion volts!
Brainiac and beyond

Now that you’ve got a class of Brainiacs why not get them to report back on the things that they have at home that are powered by electricity.

Make sure they get a grown up to help them. Which things are powered by batteries and which need to be plugged in?


Effects of air resistance

The Brainiacs challenged the audience to a fight using an airzooka invented by Lieutenant Brian Johnson from the US Air Force. An air vortex is created by the wing of an aeroplane as the air swirls off of the tip of the wing... no wonder the airzooka was invented by someone in the air force!

The airzooka uses the difference in air pressure to make a fun toy but you can show your students an amazing science trick and set them an air resistance challenge. Maybe this is one that Brainiacs could actually win at!


What you’ll need

  • A hairdryer (ideally one with a cold air setting)
  • A ping pong ball
  • Paper
  • Paper clips

How to do the experiment

Get a few students to hold the short edge of an A5 piece of paper horizontally in front of their mouth. The rest of the paper should flop down below their chin. Ask them to blow over the top of the paper and not under the bottom of it. If they do it correctly then the paper will start to rise up like the wing of a plane.

Take this experiment further; Use a hairdryer on a cold air setting, facing upwards and carefully place a ping pong ball into the air stream. Before placing the ball in the air stream get your class to predict what they think will happen. Do they think the ball will fall out of the air stream if you angle the hairdryer diagonally left and right?

Set the class the challenges of making the most effective aerodynamic shape as their plane and the most air resistant shape as their parachute. They have a piece of paper and a paperclip for each challenge. Use the hairdryer to test their results.

Why does it work?

The ‘Bernoulli effect’, named after Swiss mathematician Daniel Bernoulli, is what happens to a wing as it moves. The bottom of a wing is flat which lets air pass by it easily and keeps the air pressure the same as it was before it got to the wing. The top of the wing is like a steep slope that the air gets forced over. This spreads the air out and lowers the air pressure above the wing. This means that it’s easy for the wing to go upwards into the lower air pressure than it is to go into the higher air pressure beneath it and that is what helps planes take off.

When the ping pong ball is in the air stream of the hairdryer it has low-pressure air flowing past every side of its rounded surface. It can’t escape the low pressure of the air rushing past the side of it because beyond that is higher-pressure air. Every time the ball goes slightly out of the air stream of the hairdryer it ends up meeting the higher-pressure air and being pushed straight back into the low-pressure air.

Did you know?

Leonardo Da Vinci (1452- 1519) came up with an idea for a pyramid-shaped parachute made of linen cloth held open by wooden poles. His parachute was finally used 500 years later in the year 2000 when British man, Adrian Nicholas tested it by jumping from a hot air balloon. Thankfully it worked!
Brainiac and beyond

Can your class find any examples of nature using air pressure to its advantage?

Maybe a bird’s wing or a sycamore leaf.


What’s behind a rainbow?

Brainiacs are always looking for science where ever they go… even if that’s in their old CDs. Recently the team noticed that ED’s Frozen soundtrack CD has been casting beautiful rainbows on the wall… well, it hasn’t been making beautiful music in their ears! Get your class to explore rainbows further and the way in which we see light with this experiment.

What you’ll need

  • A prism or an old CD (It doesn’t have to be Frozen)
  • Three torches (Colour changing ones are best but if you can find them then you’ll need the next thing)
  • Red, green and blue plastic (sweet wrappers will do)
  • Paper/card with a circle drawn on each sheet
  • Elastic bands or pencils

How to do the experiment

Using a prism or a CD you can split the white light into a rainbow. Ask students to pick out all of the colours of the rainbow. Did you know that our eyes can only see three colours? Red, green, blue. Everything else is a mix of those colours. Use three torches with red, green or blue coloured plastic over the end.

Get your class to predict what colours will appear when they mix different combinations together. Mix all three together to get white light again. Is this what they expected?

Finished already?!
Get your class to draw a colour wheel. Separate the wheel evenly into seven triangles and colour each triangle to the colours of the rainbow. You can either use an elastic band or a pencil in the middle of your colour wheel to make it spin really fast. If you get it to spin fast enough the motion should make the colours appear to combine to make white.

Why does it work?

We often think of primary colours as being red, yellow and blue but this only applies to things like paints and inks. This is subtractive colour. It’s called this because light from the sun or indoor lights shine on it and it absorbs most of that light apart from the colour we see, which is reflected off of it and into our eyes. So the paint is subtracting all other colours from white light until we only see the colour that it appears as. For example; purple paint is absorbing all the colours of white light apart from purple, which it reflects.

Light works through additive colour. It gets its name because nothing is being absorbed from the colour before hitting your eye. For example, if you want to see purple light then you need to add blue light and red light together. If you look very closely at a TV (old ones are the easiest to see this on) then you can see red, green and blue pixels which is how TVs and other displays mix colour.

The colours of the rainbow are just mixtures of the three colours of light that we can see. Our eyes have cells that see just red, green and blue. Every other colour we see is a combination of those colours. Light travels in waves a bit like sound. Refraction is when those waves are made to change direction through something like the glass of a prism or the water droplets of rain. The waves are light are refracted at different angles, allowing us to see a beautiful rainbow on a rainy day when the sun is also shinning.

Did you know?

Sir Isaac Newton (1642 – 1727) originally used prisms to work out the rainbow colours contained in white light. If you looked at a rainbow from a plane then you’d see it as a circle but standing on the ground you only ever see it as an arch.

Magnetic mazes

The Brainiacs have often thought that they have magnetic personalities but it turns out they’re actually poles apart from each other… (ahem) that’s enough of the magnet jokes!

Use magnetism with your class to make a fun game and teach them some attractive and repulsive science at the same time.


What you’ll need

  • Magnets
  • Paper card
  • Counters of different materials. Mostly magnetic but some not

How to do the experiment

Get your class to draw their own mazes on pieces of paper card. Use a magnet under the paper card
to get a counter to magically move over the surface of the paper card through the invisible force of
magnetism. Try different materials as counters (including other magnets). Are some better than others?
What sort of things do the materials that work have in common?

If you’ve explored electrical conductors and insulators then ask your class if they have anything in common with some of the magnetic materials here. Are any good at conducting electricity but not magnetic?

Finished already?!
Get your class to test different objects for their magnetic qualities. Get them to lay the objects out from least magnetic to most magnetic.

Why does it work?

Everything is made of atoms and inside those atoms are tiny particles called electrons. Just like with electricity, magnets work because of their electrons. The electrons in the atoms of magnets align in a single direction. This creates a magnetic field that wraps around the magnet in a circular shape from the north and south poles at either end. This magnetic field can make the electrons align in other materials such as different type of metals which attracts them to the magnet.

Did you know?

Compasses always point to the north... but not to the North Pole. Magnetic north is always moving. It was in Canada in 2015 but heading towards Siberia. If you took a compass there then it would point to nowhere in particular because it would be trying to point to something directly below your feet.
Brainiac and beyond

Set your class a challenge to go and find some things around their home that are magnetic.

If they have fridge magnets then they can use one to help them become a magnetic detective and find five things around their house that it sticks to.

Are there any metal things that they can find that aren’t magnetic?


Elastic band guitar

Brainiac Raz showed us that, the older we get, the fewer frequencies we can hear… unfortunately, it doesn’t also improve our taste in music! One hertz is equivalent to something like a guitar string vibrating up and back down again in exactly one second. The higher the number of hertz the more times it vibrates in a second... and Raz took that 20,000 hertz!

While you may not have been able to hear it anymore, some of your class still could. But there is more to sound waves than meets the… well…ear. Get your class to play with vibrations to create sound waves of their own.


What you’ll need

  • An empty cereal box or a box of a similar shape
  • An elastic band
  • 2 pens or pencils

How to do the experiment

Use a small box such an old cereal box. Turn it on its side. Pull the elastic band over it long ways and place a pen or pencil under one end, in between the elastic band and the box. Place the other pen under the band at the other end. Move the pens closer and further from each other whilst plucking the elastic band. Get your class to make predictions about whether the sound will go higher or lower when the two pens or pencils get closer or further away from each other.
Finished already?!

Get your class to experiment for themselves with a ruler on the end of the table. See if they can count how many times their ruler vibrates before coming to a rest once they pluck it. What do they notice about the sound when they lengthen and shorten the amount of ruler hanging over the end of the table.

If you have a musical instrument or a musical tuning app on your phone then you can map the notes of a scale and get your own ruler orchestra going. You might want to put your fingers in your ears when you conduct it though!

How to do the experiment

Sound travels through vibrations. Physical vibrations in musical instruments such as the strings of a guitar push and vibrate the air around them. The vibrations travel through the air to our ears where it vibrates our eardrums and our brain interprets this vibration as the sound we hear in our head.

These vibrations are known as frequencies but this just means how frequent, or how often, something is vibrating in an amount of time. The higher the frequency, the quicker it’s vibrating so the higher the note is. The slower the frequency, the lower the note.

How to do the experiment

Animals like bats use sound to help them find a tasty treat like a mosquito or a moth. Bats send out sound waves from their nose and mouth and wait for the sound waves to bounce back to them.

They can use it to detect where an object is, how big it is and its shape. The process is called ‘echolocation’ and they can use it to find an object smaller than a human hair in complete darkness!

Brainiac and beyond
Get your budding Brainiacs to name as many musical instruments that they can think of that use vibration to make a sound.
States of Matter

Solids, Liquids and Gases

The Brainiacs found out that liquid nitrogen doesn’t stay liquid for very long. Nitrogen is a gas that we breathe in as a part of the air but the team managed to get their hands on some that has been frozen as a liquid. They thought that it would be a good idea to put it in a bottle, put the lid on and brace themselves for a loud bang as it turned back into a gas, expanding in the process. Well, every Brainiac starts somewhere… why not try a school-friendly version of this experiment and show your class the world of solids, liquids and gases?

What you'll need

  • A sealed container such as a plastic takeaway tub (this has to be air tight). An old film canister works great for this!
  • Alka Seltzer tablets
  • Some water
  • Safety goggles

How to do the experiment

Place a small amount of water (liquid) in your container. Use an Alka Seltzer tablet (solid). When it is dropped into the water it will react with the water to create carbon dioxide (gas). Make sure that you get the lid on quickly. Get the class to predict what will happen when the gas expands in the enclosed container.
Finished already?!
Try to change your experiment up a little with some variables. Use warm water and see if the reaction happens any quicker. Try the experiment using more water… and if you’re feeling brave you can try more Alka Seltzer, but remember to get your class to predict what they think will happen first! And remember to wear safety goggles.

Why does it work?

Gas takes up more space than a liquid because the groups of atoms known as ‘molecules’ that make up matter such as solids, liquids and gases, want to push out in every direction. If you do a fart in a room then the fart molecules will fill the room by expanding outwards.

The molecules in solids like to stick together in rigid structures so they can’t move around easily. In liquids, those molecules can move freely but are still quite close to each other. In a gas, they push out in every direction that they can and when there is no more space left…. POP!!!

Did You know?

Paint is a liquid until it dries into a solid when it reacts to the gases in the air, but did you know that the largest passenger plane in the world, the Airbus A380 is 1.1 tonnes heavier after it’s been painted! It takes a team of 34 people a whopping 6,000 hours to paint it…. That’s like you and your entire class being at school well over an entire year and doing nothing but painting the entire time!
Brainiac and beyond

Why not get your class to identify different solids, liquids and gases.

Get them to list three of each.