NEAP Trial 2006 q31 (pauli & heisenberg) (1 Viewer)

[matty fwd]

Ok this question was worth 7 marks, but the recommended answer in the answer booklet was too basic.

d) The physicists Werner Heisenberg and Wolfgang Pauli had a significant impact on our understanding of the structure of the atom.

Outline the contributions of each man and compare their respective influences on the current theory of the internal structure of the atom.


sample answer (summary): - pauli exclusion principle..supported sub-orbitals
- hesienberg uncertainty principle..charge cloud model

If this question was in the HSC exam, what would your answer be?

 

[alcalder]

Pauli proposed the Pauli exclusion principle which stated that no two electrons in an atoms can have exactly the same set of quantum numbers. The quantum numbers n, l, m<sub>l, and ms, describe the energy of the electron (and dictate the orbital level), angular momentum of the electron, electron magnetic number and electron spin respectively. Essentially Pauli was saying that there is no room in an atom for all electrons to remain in the lowest energy state. As energy levels fill, further electrons are forced into higher energy states.

This undersatnding allowed scientists to predict the behaviour of electrons in atoms larger than Hydrogen and can explain the grouping of certain properties in the periodic table.

Heisenberg proposed the Uncertainty Principal. This essentially states that there is an inherent error in determining both the position and momentum of electron at the same time.

∆x∆p >= h/2π

∆x = error in determining position
∆p = error in determining momentum
h = constant = 6.626 x 10^-34

To know either the position or momentum exactly the error in the other must be relatively large on a quantum level. Thus scientists are unable to say exactly where an electron is with a particular momentum and hence there is a certain probability of a electron's position within a certain region.

I think that may do it. Does that help?</sub>

 

[matty fwd]

Certainly does, thanks heaps alcalder. But I've seen other people answering this question, mentiong Heisenberg's mathematical development..."matrix something" and also mentioning Pauli's discovery of the neutrino.... reckon they're necessary?

 

[alcalder]

Certainly Pauli's discovery of the neutrino is significant because it showed there were other particles inside the atom. Scientists then went looking for more.

Heisenberg had a bigger contribution to the model of the atom. He also rejected the mechanical model and went in search of a mathematical model and this is essentially where quantum mechanics comes from. It is entirely mathematical and all they know about the atom now comes from that mathematics.

If there are other things you know about Pauli and Hesienberg that contributed to the understanding of the atom then include it and make sure you link it to the influence on the current theory.