# Homework Help: 2 Atomic Physics questions - Pauli exclusion principle

1. Jun 23, 2013

### daleklama

1. The problem statement, all variables and given/known data

Q1. Briefly explain the relevance of the Pauli exclusion principle for the structure of the periodic table of the elements.

Q2. What is the maximum number of electrons that can be located in an atomic subshell with quantum numbers n and L? Briefly expain your answer.

2. Relevant equations

Well, I know that the Pauli exclusion principle states that:

No two electrons in the same atom can ever be in the same quantum state. Therefore, no two electrons in the same atom can have the same set of quantum numbers.

3. The attempt at a solution

For the first question, I just don't really understand what answer they're looking for! I understand the Pauli exclusion principle, but I'm not sure of its relevance to the periodic table. All I can think of is that without it, all the electrons in the atom would simply fill up the lowest subshell? And then the elements would be arranged differently? :/ Or maybe there's something else I'm overlooking entirely!

For the second question, I'm also not sure what they're asking.
I know, for example, that the 1s, 2s, 3s (etc) subshells can fit a maximum of 2 electrons, and it's a maximum of 6 for the p subshells, a maximum of 10 for the d's. I don't know where n and L come into it though... shouldn't I be given actual numbers for 'n' and 'L'?

Any help is very appreciated!

2. Jun 23, 2013

### Staff: Mentor

Subshell?
You are on the right track here. Without the exclusion principle, how would all atoms look like?

The answer is a formula with n and l in it.
"s" corresponds to l=0, for example.