What Do These Physics Forum Terms Mean? A Quick Guide to Lingo

[The Bob]

I am starting this thread for me and anyone that doesn't understand any language used in the PF forums post it here so people can say what it stands for. I have been confused once or twice in these forums. Anyway it will probably turn into something unusual like the other threads.

Anyway here are my words to check:
1. Quanta
2. Valency
3. QED

Cheers

The Bob (2004 ©)

 

[Moonbear]

I am starting this thread for me and anyone that doesn't understand any language used in the PF forums post it here so people can say what it stands for. I have been confused once or twice in these forums. Anyway it will probably turn into something unusual like the other threads.

Anyway here are my words to check:
1. Quanta
2. Valency
3. QED

Cheers

The Bob (2004 ©)

I have a working understanding of quanta and valency, but would probably miss something important in the definition without looking it up and using someone else's definition, so I'll leave that for the physicists/chemists to answer.

QED - Quod erat demonstratum
Oh, you probably want that translated too.
It's Latin for "That which was to be proven." You use it in the final statement of a proof, when you've reached the conclusion intended.

 

[Gokul43201]

QED, if it appeared in a physics subforum, would be Quantum Electrodynamics - the Quantum theory of the interactions of energy with matter.

 

[Gokul43201]

I believe there was a thread like this before, listing all the abbreviations/jargon used in PF.

 

[The Bob]

I believe there was a thread like this before, listing all the abbreviations/jargon used in PF.

Ok. Cheers. I am still likely to post it here though.

The Bob (2004 ©)

P.S. Thanks for the QED. I thought it knew it. Just comfirmed it.

 

[Andy]

This taking a guess but isn't a quanta a unit of energy? I am really not sure about this but i have a strange feeling between my toes telling me that it is.

Might just be athletes foot though.

 

[Moonbear]

QED, if it appeared in a physics subforum, would be Quantum Electrodynamics - the Quantum theory of the interactions of energy with matter.

Latin came first, how dare they steal the abbreviation! Well, I guess it's a good thing The Bob asked, and now I'm doubly glad I didn't try answering the other two.

I always get good laughs discussing the abbreviation AI with one of my friends...he's an engineer, and I'm a biologist...our first thought of what the abbreviation means are two VERY different things...he says it's artificial intelligence and I insist to him it's artificial insemination. But you all might be able to settle things for us if anyone can tell me when the term artificial intelligence was first used. We've been trying to figure out which one came first, but I think they may have both come about at similar times (I'm not telling him that though ...I'm still insisting artificial insemination came first, which is of course why it's the correct use of the abbreviation )

 

[Gokul43201]

Quanta are discrete packets of energy. If you have radiation of some frequency, f, then the total energy of the radiation must be an integer multiple of 'hf' - which is referred to as a quantum of energy. 'h' is the Planck's constant ~ 6.626 * 10^-34 Js. A quantum of electromagnetic radiation is a photon.

Valency is the number of electrons that need to be added or removed from the outermost shell of an atom to make it have a fully filled outer shell. Sodium (Na) has 1 electron in its outer shell. It is easier to remove this one electron than to add 7 more to fill the shell. Thus, Na is said to have a valency of +1. Oxygen has 6 electrons in its outer shell, and finds it easier to add 2 electrons to fill this shell. O has a valency of -2. When Na reacts with O, the O atom takes 1 electron from each of two Na atoms (which are happy to give up an electron each). Hence the compound that is formed has the formula Na2O. Thus the valencies determine the ratios in which different elements react to form compounds.

 

[The Bob]

Valency is the number of electrons that need to be added or removed from the outermost shell of an atom to make it have a fully filled outer shell. Sodium (Na) has 1 electron in its outer shell. It is easier to remove this one electron than to add 7 more to fill the shell. Thus, Na is said to have a valency of +1. Oxygen has 6 electrons in its outer shell, and finds it easier to add 2 electrons to fill this shell. O has a valency of -2. When Na reacts with O, the O atom takes 1 electron from each of two Na atoms (which are happy to give up an electron each). Hence the compound that is formed has the formula Na2O. Thus the valencies determine the ratios in which different elements react to form compounds.

Thanks about this part Gokul. It has been annoying me for ages not knowing what valency is.

I will think about what you said and re-read the part about quanta because it is not making sense to me at the minute. Cheers all the same

The Bob (2004 ©)

P.S. Oh and not to forget Moonbear with the QED version I wanted. Cheers darling.

 

[Andy]

I was kinda rite in the vaguest possible way.

 

[Gokul43201]

I will think about what you said and re-read the part about quanta because it is not making sense to me at the minute. Cheers all the same

The Bob (2004 ©)

I wouldn't expect it to. There's a lot of reading that needs to be done to fully appreciate quantization of energy.

Check these out :

http://www.google.com/search?hl=en&lr=&ie=UTF-8&oi=defmore&q=define:quantum

 

[The Bob]

I wouldn't expect it to. There's a lot of reading that needs to be done to fully appreciate quantization of energy.

Check these out :

http://www.google.com/search?hl=en&lr=&ie=UTF-8&oi=defmore&q=define:quantum

Oh hex. I need to start reading

The Bob (2004 ©)