Can you explain electricity to me, please?

[roisin]

I have vague memories of a physics teacher talking about ping pong balls, and it just never made sense to me.

Now I've got ds1 banging on about atoms and electrons, and I still don't get it.

and when your head stops aching have a shufti at this

\link{http://en.wikibooks.org/wiki/Current,voltage_resistance_and_Ohm's_law(GCSE_science)} electricity\

what#s the egg thing?

To nit pick, I trained as a biochemist, that is my degree, but moved to physiology/ neurology/ pharmacology....I'm a biologist at heart. I teach everything up to the end of KS3 (most science teachers do this). I mostly teach ks4 and ks5 biology.

Soft biol and egg and remove the shell.

Light some paper and put it quickly into a milk bottle. As it burns , it uses up the oxygen and makes carbon dioxide and water. Because water is a liquit, the atoms are much closer together , so the gas pressure in the bottle is dramtically lowered. Te pressure outside is then greater than inside the bottle and the atmospheric pressure pushes the egg into the bottle.

Great fun, very messy and dramatic!

startingtobehalloweenylover (who are you btw?) for egg thing and other fun science see this thread

i am starlover!

sounds like fun but we have no milk bottles

Another day - because I really must go to bed: busy day tomorrow - can you let me know your thoughts re single science v double award combined science?

We have no milk bottles either. Is it illegal to nick them from someone's doorstep?

Double unless the child is totaly sure that they want to do 3 sciences at A level. It keeps all their options open and doesn't tie them down too young....and I'm a dyed in the wool scientist and did separate sciences myself

But if they probably want to do 2 or 3 sciences at A level, does the double award not put them at a disadvantage?

(sorry went to bed!)

Not really, at least not in Edxecel, which I know most about,. They do another gcse's 'worth' if they do all three, but we go over all the extra stuff at AS anyway. Kids also find it hard to do the extra stuff and can feel a bit discouraged. Things are going to cjhange next year anyways, as the science curruculm is getting an overhaul

Dont know if your still on electricity Roisin but there was a teacher on the radio who made brilliant sense..
He organised the kids in a ring, or circuit in the class room, made some of them into resisters, bulbs etc and then passed round malteasers! The 'resisters', I assume, ate some of the malteasers, while the circuit kids just passed the sweets on.. Missed some of the explanation but the idea of malteasers as electrons just seemed so right!

Dont know if your still on electricity Roisin but there was a teacher on the radio who made brilliant sense..
He organised the kids in a ring, or circuit in the class room, made some of them into resisters, bulbs etc and then passed round malteasers! The 'resisters', I assume, ate some of the malteasers, while the circuit kids just passed the sweets on.. Missed some of the explanation but the idea of malteasers as electrons just seemed so right!

To nit pick, the maltesers are the energy that the electrons (the kids are the electrons) pick up as they go through the battery. If you let the malteasers represent the electrons the kids end up with the idea that the electrons get used up as they go through the light bulb, which they don't. Only the enery gets used up, the electrons ie the current stays the same,. What changes is the energy the electrons carry....the potential difference.

I do this with the kids and it works well.

Completely off topic but I've eaten 4 fun sized bags of Maltesers and I feel sick.

LMAO, I've eaten 4 fun size ,mars bars and I feel sick too! is what I look like!

Oh I just bought two big bags of fun size maltesers for the school Christmas Fayre.

If I sit here and eat them instead, will I understand electricity?

PS I have no idea what a resistor is. But I think I need to know whether the resistor gets to eat more or fewer maltesers than the light bulb

You may understand electricity better but you will also feel sick. Trust me.

The resistor is a big green mosnter that makes it very difficult for the little elctrons to pass through him.

He makes it so hard that he can even begin to heat up! (this is how electric bar heaters work....the electrical energy carried by the electrons ....the malteasers get gobbled up by the resisted and given off as heat and a little bit of light!)

In a light bulb the wire is so thin, that the energy is converted into light and some heat.

Energy cannot be created or destroyed, only converted from one form into another. So we go

Chemical electricity in the battery converts to electrical energy given to the electrons, electrical energy to heat and light energy (via the resistor/bulb.

Doesn't the heat melt the chocolate or am I getting confused?

I wish I'd had a physics teacher like you at school Martianbishop!

ROFL at SoupDragon

No, soupie, please pay attention. I eat the things too bloody fast for them to melt!

Kind to say that Roisin, but I'm seriously crap at physics

Do you not sometimes think it's easier to explain something if you found the concept hard to grasp yourself?

I've only done a couple of Maths covers, and I found it extremely frustrating, because I just couldn't understand why the kids couldn't do the work. (Yr9s - very simple addition of fractions: they were trying to make it more complicated because they hadn't really grasped the concepts behind it; just the method.)