“Why does every country have different plug sockets?” asks Harry (10)

Thanks team. The third socket, the Earth socket is sometimes called the ‘grounding socket”. Lets try to make our own circuit to find out a little bit about this.

You would need a battery, some wire, a light bulb in a bulb holder and let’s say a cup with some damp sand in it.


Push the earth wire into the wet sand and see what happens.

The Earth socket on a UK plug is designed for problems where the electricity that you are using becomes unsafe, for example a wire inside a washing machine touches the case that the machine is contained in. The case it attached to rubber, non conducting wheels. You touch the case, with your leather soled shoes and you then get an electrical shock. If the case is attached to the earth wire the electricity finds an easy route to escape and this causes safety switches to open in the fuse box of the circuit. In the old days it would make a fuse melt and thus break the circuit.

The Earth socket is therefore a safety socket. Lots of appliances nowadays are so well insulated (protected) that an Earth protection is unnecessary. Some plugs have a plastic third pin. Two pin plugs have never had this additional protection.

Another experiment that you might like to try is changing the wet sand for other materials. Try leather, metals, china, dry sand, cloth ….. all sorts of materials. What an experiment! Brilliant.


(updated 18/5/2017)

Liam (10) asks “Why does electricity go around a circuit?”


Thanks for that team , a very informative introduction. It’s usually the furthest electron that is involved in moving the electrical energy around the circuit.

I have tried to create a small animation to show how this might happen. The ‘pipes’ are the copper metal wire. the dots are the outermost electron attached to the numerous copper atoms. The battery is the ‘motor’ that makes the electrons move. To find out a bit more about how the battery work have a quick look at Sadies question.

Electrons are negatively charged particles so the negative terminal of the battery is ‘pushing’ the electrons while the positive terminal of the battery  is ‘pulling’ the electrons SO when the switch is closed all the electrons in the circuit start moving together.

Who do you think discovered that opposite charges attract and negative charges repel?

Now what about the filament in the bulb. Any idea why that starts producing light? Any thoughts on both these questions, let me know in the ‘Leave a Reply ‘ box.



Sadie (8) asked “How do batteries work?”

Sadie, many thanks for your question. I asked my friends to help me…


Yes I remember doing that, it wasn’t easy but I did get the led to light up.

Let’s start with a possible definition of a battery – It’s a device that converts chemical energy into electrical energy. If you are uncertain about what I mean by energy then have a look at this site.  

Now why do we have two different metals? Inside the squeezed lemon is a lot of lemon juice. There is a chemical reaction between the metals and the lemon juice. Because the metals are different they react with the lemon juice in different ways. The different reactions give the copper nail a positive charge and the iron nail a negative charge.

Connecting the two nails together with a wire will give you a flow of electrons in the wire from the iron nail to the copper nail. This will continue until the chemical reaction inside the lemon reaches completion.

Your normal battery is like the lemon but obviously made of different materials. Look at the diagram below.

Sadie, I hope you have found this useful. If you or any other reader would like to make a comment please fill in the Leave a Reply box below. And if you are uncertain about bits of the explanation please ask another question.

Additional note …copper nails are difficult to get hold of so why not use a small piece of copper tubing. Also there is a small possibility that a battery was produced over 2500 years ago, see The Baghdad Battery. Ask your teacher about it. Or ask another question.

Akshita (12) asks “In a circuit of 5 light bulbs and 2 batteries why do all of the light bulbs come on at the same time when you switch the switch?”

Hello Akshita, I asked my friends about your question.

Thank you team. You are right metals are much more important than the plastic coating. You could replace the plastic coating with paper or rubber or cloth BUT the metal has to be a metal. Why. It’s all to with things called electrons. Most elements

  • An element is a group of atoms that all have the same number of protons (positively charged particles) in their nucleus. Oxygen is the most abundant element on the Earth, Iron is the most abundant metal element.

have electrons that are tightly held by the nucleus but metals are different. The outer electrons of metals are rather loosely held by the nucleus and are free to move around within the metal structure. So if we looked at a circuit which was not connected to a battery (switch is Off) and looked closely at a small section of the wire you would see something like this …

The little red dots depict the outermost electrons of the metal atoms (the element nuclei are the positive circles).  You have to imagine that the electrons are constantly moving around within the metal structure and probably keeping quite close to their parent atom.

Now close the switch.

The battery is now pushing the electrons around the wire (- to +). This push is a bit like a long chain being pushed or pulled. All the electrons in the wire experience the push simultaneously (like the links in the chain) so when the switch is closed all the lights in the circuit will experience the ‘push’ and the electrons in the vicinity of the bulb filament will give up some of the energy of the push to the filament which will be converted to heat energy and create a hot filament which is then partly converted to light energy.

This is a lot to think about Akshita, you, and any other reader can ask another question or Leave a Comment in the Reply Box below.

Makeda (7) asked “How does the electricity make a magnet?”

Makeda what a great question, and my answer is, I don’t know. We know that electricity can make a magnet or even give a wire magnetic properties. There are other things which we know but it’s a bit like gravity. We know that big things, like the Earth and the Sun attract smaller things – the Sun attracts the Earth, the Earth attracts you and me BUT we do not know what gravity is, we just know what it does.

So I asked my friends about this.

Absolutely, thank you friends. Electricity is linked to things called electrons that are attached to other things called atoms that make up all of the things that we see around us, and us.

There are some special materials that you might have discovered called ‘metals’. Metals allow the stuff which we call electricity to flow through them. In metals the electrons carry the electricity and when they start moving they not only start moving the electricity there movement creates a magnetic field.

So lets carry out some experiments to investigate electricity and magnetism.

Let us make a simple circuit with a battery and a switch  and add a compass, close to the circuit.   Why a compass? A compass is a very small magnet and will detect other magnets by trying to move towards them or away from them. Switch on the circuit and see what happens. Switch off and again see what happens.


Let us know what you saw.

How strong is a thunderstorm? -asked Jessica (8)


Many thanks for your comments team. Yes you are right, to create a thunderstorm you need a lot of warm water. It’s development goes by the following crude set of stages …

  • Lots of warm water evaporates (turns from a liquid state into a gaseous state.). Thunderstorms are therefore more common in the warmer regions of our planet.
  • The gaseous water is forced upwards by the warm sea. The warm sea warms the air close to it. This air expands and is therefore becomes ‘lighter’ and moves upwards carrying the water vapour (water vapour is the term used to describe gaseous water) with it.
  • As the gaseous water rises it gets colder (more distant from the warm sea) so it becomes water again (small drops of liquid water). A cloud begins to form.
  • The heat from the ocean continues to make the water and water vapour(clouds) rise.
  • It gets even colder and more of the water vapour turns back to water.
  • Some of the water droplets in the cloud turn into ice particles.
  • The ice particles separate some move to the top of the cloud others remain in the bottom.
  • This split causes an uneven distribution of electrical charge in the cloud.
  • The result is Lightning and Thunder.
  • Some of the frozen water falls away from the cloud. this causes all sorts of down draughts and strong winds are created.
  • Some of the ice does not melt as it falls through the air – this forms hailstones.

You could look at this question http://www.sciencemaster.co.uk/2016/11/18/elizabeth-9-asked-a-question-on-lightning/


Any questions, please leave them in the `Reply Box’

Elizabeth (9) asked a question on lightning

Elizabeth, thank you for your question. “How many %C is the air surrounded by lightning?” I am sorry that I had a difficulty in understanding it. Are you asking about the temperature (degrees C) or are you asking about the Carbon (C) in the air ?  As it was a question about lightning I thought I could ask my friends to talk about that. If you want to revise your question you can easily ask it again. lightning-strike

Thanks team, some very interesting observations.

What I find interesting is how does lightning happen. It’s all about clouds. Hot weather produces lots of evaporation of water from our oceans. The hot air and water mixture rises, look at the clouds from a kettle. As it rises, the cloud of water vapour and air gets colder, and colder. The water turns into very small ice crystals which are still lifted by the cloud of air that they are in. As this happens it is thought that the ice particles separate ……. the lighter particles move to the top of the cloud while the heavier particles remain at the bottom.

The water/ice particles have a small electrical charge associated with them. When they separate the charge moves with them. It is likely that this causes an uneven redistribution of the total electrical charge. If you have more lighter water/ice particles at the top of the cloud than heavier ones at the bottom the difference in the total charges could be significant. So ‘flash’ they try to equalise and thus the lightning flash. It’s the process of the ice crystals at the top of the cloud trying to get rid of their excess electrical charge by giving it to the heavier ice crystals at the bottom of the cloud.

Sometimes difference in charge is so great that the ‘flash’ continues to the ground, but if you are in a storm and look at the flashes a lot of them are within the clouds themselves.

Elizabeth, sorry for such a long explanation. It was such an interesting question. If you have any other questions linked to what my friends and i have said please ask them.

Elizabeth. Some additional information ……. Look at this site. The type of electricity that is built up in clouds , before the lightning flash is static electricity. There are some experiments you could try.

(added 20/11/16

Rainie (8) – asked “How do touchscreens work on phones?”

Rainie – what a question!  I thought I would start by presenting my team with the question….


Rainie it’s all about electricity. Think about the ‘stuff’ that comes from batteries that makes your watch work or makes a torch light up the world. Electricity travels from place to place by travelling through things that allow it to travel through. It cannot travel through paper, plastics, stones and other things. It can however travel through water, some special glass, metals and you.

When you touch the screen of your telephone, you are allowing a very small amount of electricity to travel from the glass to you. The phone recognises this and knows where you have touched the screen. It then responds to the touch.

An experiment – touch the screen using a variety of materials on your finger. Try a damp finger, a finger covered by cloth, paper, aluminium foil, plastic and maybe a leaf. I am sure you can think of other materials. This little experiment might lead to other questions so please ask them.

Remember Rainie do not under any circumstances play or experiment with mains electricity. It could hurt you badly.

Why does your hair stand up when rubbed with a balloon? was Kim’s question

Kim. I think we have something called ‘static electricity’ at work here. I asked my team to try to explain what ‘static electricity’ is.

As my friends have said we have met electrons before. These were moving  electrons. They were moving along a wire carrying their charge with them. Here we have electrons that are not moving, but they still have an electrical charge, so they are static.

Lightning is thought to be caused by static electricity collecting in clouds.

But now for your question Kim. When you rub your hair with a balloon. Some of the electrons are moving from your hair to the balloon. Or it might be the other way around …. some might be moving from the balloon to your hair. At the moment we don’t know which is happening. However whatever way it happens one of the objects (hair or balloon) loses electrons and becomes positively charged and the other object (hair or balloon) gains electrons and becomes negatively charged. Then we apply a famous rule about negative and positive charges …..like charges repel, unlike charges attract  soooooo  because we have a negative and a positive charge we have attraction. Your hair is attracted to the balloon, the balloon is attracted to your hair.

think you could work out a way to find out which of your two materials (hair or balloon) is the collector and the giver.

Have a think. You can then give your answer in the ‘Leave a Reply’ box or Ask another Question.