different explainations on pauli's exclusion principle..*confused* (1 Viewer)

[unfold]

hey peeps,

i looked over different study guides..and they all have different explanations... e.g. macquarie guide: 'only two electrons of opposite spins can occupy any one energy level in an atom'

e.g. excel: 'no more than one electron in the same atoms can have all four quantum numbers the same'

WHAT THE...? can some one please explain? are they talking about the same thing???

thanks in advance

 

[Captain Gh3y]

In 1925, Wolfgang Pauli developed his exclusion principle. This principle states that no two electrons in an atom can have exactly the same quantum state. Electrons are identifiable by four quantum numbers:

1. Principle quantum number (n) – The shell number of the electron
2. Orbital quantum number (l) – The shape of the orbital l = 0 would be a circle, as l
increase, the orbital becomes a more squashed ellipse (0 ≤ l ≤ n)
3. Orbital magnetic quantum number (m l) – The orientation of any orbit around a
nucleus (-l ≤ m l ≤ l)
4. Spin quantum number (m S) – While orbiting the nucleus, the electron is spinning
at the same time, either clockwise (m S = +0.5) or anti-clockwise (m S –0.5)

No electron can have all of these quantum numbers exactly the same according to the exclusion principle. If this principle did not hold, all of the electrons in an atom would pile up in the lowest energy state.

The introduction of spin into the quantum theory accounts for the observed electronic structure of the elements (2, 8, 8 etc.) and the hyperfine spectral lines (zeeman effect). It also explains the Periodic Table of the Elements.

...

To be honest, those 4 numbers aren't all that meaningful to us, they don't really tie in with anything else from this topic; this dotpoint (Pauli/Heisenberg) is rather isolated. I don't know what the chances are of this dotpoint appearing in the exam are (as being worth any significant amount of marks), and if it doesn't then this stuff isn't all that important anyway.

Edit: The Pauli and Heisenberg dotpoint has, in fact, not been examined yet. Probably safer to know this, then.

 

[Haku]

i never heard of this, is this part of the syllabus?

 

[Xenocide]

yes it is, something to the effect of "outline pauli's and heisenberg's contributions to quantum theory"

 

[robbo_145]

ie. part of Quanta to Quarks option topic......

 

[spank_meh]

ie. part of Quanta to Quarks option topic......

phew!!! why didnt anyone mention that at the begining haha coz i was like wtf were did that come from

 

[Haku]

lol, i do med phy. so its ok i never heard of it

 

[rnitya_25]

hahaha same here! i got scared for a sec....like what the hell....never even heard of them. i do medical physics too nosadness....how do you find it?

 

[Haku]

its pretty simple, mainly comprehension types, so need minimum brain power, but large harddisk is required. So its a nice contrast to the trend on core physics with the trend of now applying knowledge.

so it rest the brain. but hate the spin part, it was never tested so maybe this yr is will or it never will appear.