Electrical Energy Part 1

With our assumption, the 3 protons, 3 neutrons, and the first 2 electrons are merged into one dot. This dot has a positive charge because it has 3 + protons vs only 2 - elections. So, it is net 1+, and is shown as a +. It then has a - Valence electron buzzing around.

Look at how that Valence electron behaves.
What would you say about how 'bound' that Valence electron is to it's atom?
Does it stay with its local atom or is it 'delocalized'
How would you describe it?
Then add a charge to once side - what happens now?

The Durde model Interactive is good for seeing the 'Sea of Electrons'.

This sharing of electrons through the sea of electrons gives metals their properties

Every + charge needs to be balanced by a - charge.

So lithium always needs a negative valence electron - who's it is doesn't matter

It's like a shared lunch. Everybody gets to have lunch, it just might not be the lunch you brought.

Or its like a person who hates to be alone. They have to sit with a friend all day long, but because the classes are different, the friends will be different at various times during the day.

A lithium atom has a strong force of attraction to an electron. Still, because these electrons are moving and shared, the neighboring lithium atom also has a strong force of attraction to the electron (not strong enough to stop the sharing). This strong force of attraction makes metals solid (except mercury) because they need to be very close to each other to share their electrons.

The positively charged nucleus is in a fixed position in the metal, but the electrons are in constant motion. They move randomly all over the place. But you could move them in one direction.

With the Drude model above, what happens when you put a charge on one side of the metal?

When the sea moves, it is a current. When a sea of electrons moves, you have an electrical current.

Note that you must replace the moving electrons with new electrons—the metal atoms will not allow their electrons to move unless they are replaced. Because of this, you have to have a circuit for the current to flow around.

Static Electricity

Below are two non-metals. You can move electrons away from some non-metals, like trampoline mats, woolen socks, jackets, plastic slides, and balloons. If you can remove electrons from something, it will want new electrons to replace them.

If a kid slides down a plastic slide, the slide will take some of their electrons - they will take some of you electrons to fix this imbalance - this will hurt you a little bit
If a kid, especially wearing socks, is jumping on a trampoline, the trampoline will take some of their electrons - they will then take some of yours if you help them off the trampoline - sometimes the kids know this so they will try to 'shock' you - however it is actually you shocking them as the electrons are going from you!
If you wear socks, like John Travolta below, then touch a metal door, you will receive a shock - how does this work, especially as Metals need to say in balance with their number of electrons - if they don't they will corrode and fall apart. So how come the metal door handle isn't corroding?

Van de Graaff

youtube.com/shorts/xtM1PbrG-ck

shocking

In the clip to the side, a rubber strip is rubbing against an acrylic roller, removing electrons from the acrylic. The metal dome protects this. The metal dome develops a positive charge as it tries to give electrons to the acrylic, if you touch the dome it will take your electrons - making your hair stand up as you now have a net positive charge and your positively charged hair strands will repel from each other. The metal needs to keep its electrons in the same number, so it develops a charge due to the acrylic that has lost electrons, but the metal is not moving its electrons.

So, there is a high charge but no current (an incredibly small current)

This high charge without a correlating current results in the Van de Graaff machine being somewhat safe.

The larger the charge difference is, the larger the Voltage

Which is the Killer, Current or Voltage

Watch the Clip above and formulate your answer!

Conductors Vs Insulators

Conductors share their Valence electrons in a 'sea of electrons'. They have a low attraction between their valence electrons and their nucleus. Thus their valence electrons are 'delocalized'. These are metals and include: gold, copper, lithium, iron, aluminium.

Insulators do NOT share their Valence electrons. They have a high force of attraction between their valence electrons and their nucleus. Their electrons are thus 'localized'. This includes: Plastic, rubber, polystyrene.

If you force a insulator to conduct by giving it a very very high voltage, then it will get hot and burn and catch fire.

Try making circuits with this PHET interactive. Then swap out the insulators and conductors. The 'lab' option is the more interesting option

Earth

The earth is the cheat code for Electrons. It has an infinite supply of electrons, so it can give them away or take them, and because the earth is so big, it stays neutral.

So electrons want to go back to the start of their circuit, or they want to go to the earth - whichever is easiest.

Because of this, you need to wear shoes when working with electronics, especially outside. The current might find it easier to go through your body to the earth, making a shortcut out of its circuit and straight into the world through you!

When using products with metal casings or electrical tools outside, they must have an Earth wire - this is the third prong in the plug. This will ensure that if the wire breaks inside your tool and touches the metal casing, the electricity will go to the earth through the earth wire and not through you. Look at your metal things; they all have ground wires: washing machine, microwave, fridge, Alienware Aurora PC, toaster, kettle, and Iron from Briscoes.

If you are using an indoor tool that is all plastic and rubber (insulators), then it might not have a ground wire because there is no metal conductor to shock you with—e.g., your laptop charger or phone charger.

An Earth wire means that if the metal casing becomes 'live', it will be easier for the electricity to go through the Earth Wire to earth than it is to go through your body. Electricity will choose the path of least resistance.

Without an Earth wire, the electricity will go through your body to the earth, and that will be bad

As you can see, my 850Watt Alienware PC has a 3 pronged plug

Where as my Microsoft Surface just has a 2 pronged plug

This is for 2 reasons

The PC is taking 240Volts and 4Amps, so any short circuit is dangerous to me and can destroy the motherboard - so gounding it means that a short circuit will be taken outside of my house to my grounding rod - thus keeping me and the PC safe
The Laptop has an adapter that turns the 240V way down to 15V (but still a deadly 8Amps - but the voltage is too small to push those Amps over my skin and to the ground
The Laptop adaptor is completely covered in plastic and rubber - these are both insulators - keeping me safe from any shorting in the adaptor
Distrubingly enough - I do still get a 'sensation' from my laptop if it is charging - so they probably should have an earth IMO.

Lightning

As you increase hight above sea level, the air gets colder - hence snow on the tops of mountains.

As water droplets are pushed upwards in a cloud by updrafts they form small ice crystals, over time more water vapour condenses and freezes on these crystals and the ice becomes too heavy to be held up by the updraft and starts to fall down. As they fall some of the water vapour that condenses on them might not get the time to freeze, this makes the outside of these big ice crystals liquid - like a small piece of hail that you pick up - the outside is slippery and wet

On its way down it will bump into small ice molecules

The liquid water is will happily take electrons from frozen water

So, the big one falling will become more negative as it collects electrons. The tiny ice crystals going upwards become more positive.

This makes the small ice slightly positive and the big slippery ice somewhat negative.

This doesn't matter at first; however, once several trillion molecules have done this, the parts of the cloud will develop a charge: positive at the top of the cloud and negative at the bottom of the cloud.

As more small ice and big slippery ice exchange electrons, the voltage difference between the top and the bottom of the cloud can become millions of volts. Eventually, those electrons want to go somewhere

They can go back up to the top - this is lightening inside a cloud

Or they can go to the Earth!

scied.ucar.edu/interactive/make-thunderstorm

scijinks.gov/zap-game/

Batteries

How Do Batteries Work | An Introduction to BatteriesBatteries store electricity and provide an easily accessible energy supply. An efficient method of electrical energy storage uses reduction-oxide reactions, also known as redox reactions.

Voltage is the size of the difference in charge. Because this is all it is, you can get massive voltages like 200,00 Volts and still touch it.

Voltage is a difference in charge (+ and -). The size of the difference is given a number, e.g., 12 Volts - like a 12 Volt battery. This 12 Volt is a difference in charge sufficient to Force negatively charged electrons to move. If the electrons do not move, due to the battery staying in its packaging at Bunnings, then the difference in charge between one side of the battery and the other will remain 12 Volts

Once you plug the Battery in, electrons will move from the area of high negative charge (due to repulsion), to the area of high positive charge (due to attraction). But as you do this, the size of the difference will reduce.

Electrons need to be both pushed and pulled in order to move.

This is why you have a -ve and a +ve on a battery.

The -ve has an excess of electrons

The -ve side is called the anode (a negative electrode)

The +ve has a lack of electrons

The +ve side is called the cathode

The bigger the difference between the excess and the lack, the bigger the Voltage.

So a 12V battery has twice the difference that a 6V battery has.

The electrons will only move if there is a circuit for them. Otherwise, they will sit on either side of this dam.

Your 12V battery might start with 12 Volts, then you use it for a night with your torch, then your torch goes flat. The battery might still have 11 Volts, but this is not enough of a charge difference to force enough electrons to go through the light bulb to make the light bulb light up. But you might still be able to use the battery in your TV remote.

Resistance, Current, Voltage and Energy - An introductory scenario

It takes 1 Joule to move 6 Quintrillion electrons past a point in 1 second with a charge difference of 1 Volt.

If we used 2 Joules, then we are either:

Option 1

Moving 12 Quintrillion electrons with a charge difference of 1 Volt

Option 2

Moving 6 Quintrillion electrons with a charge difference of 2 Volts

The option chosen will depend on how much resistance to moving those electrons there is.

The greater the resistance, the more Voltage it will take to move the electrons

So, option 1 for low resistance, and option 2 for higher resistance

6 Quintrillion electrons are how many electrons pass a point for 1 Ampere

1 Amp = 6 Quintrillion electrons

Rechargable batteries use energy to move the electrons back to the other side through another circuit to start this journey again. This is known as 'charging' your battery (phone). Using the battery is known as 'discharging'.

Electromagnetic Induction

Have a play in Faraday's Electromagnetic Lab below

What does the magnet to do the current in the wire?
What happens when you stop moving the magnet?
What happens when you increase the number of coils on the wire?
What happens when you move the magnet slowly compared to quickly?

Electrons have tiny electric fields. Because electrons move randomly, their magnetic fields cancel each other out.

But if you move a magnet near a wire, the electrons will organize their fields to be opposite to the magnet - this organizing moves the electrons. Then they will stop

But if you keep moving the magnet along the wire, the electrons at each point will have to organize themselves, so they move too.

As long as the magnet is moving, the electrons will move. It takes work to move all those electrons, and you they resist this work.

You can see this when you drop a magnet through a hollow wire (aka a pipe). The magnet will fall slowly as it is having to move all those electrons

Having to run a very long magnet along a very long wire will take a long time. So it is easier to make a coil of wire - a coil of wire has a long wire all coiled up.

Then instead of running your magnet all the way along it, try spinning your magnet

As long as something is moving (either the wire or the magnet, you will induce an electromagnetic field in the wire and the electrons will be moving. When the magnet (or wire depending on what you are spinning) stops, the electrons stop moving and the electric field stops and everything stops.

To make the magnet (or the coils) move you need to do some work. You need to put energy into the system. The energy you put into the system, by doing work with the magnet - spinning the turbine - will be almost equal to the work that you can do with the system (some energy is lost due to heat)

This is why hydroelectric dams have to be so big.