# Homework Help: Electron Configurations Phosphorus

1. Mar 20, 2013

### nobodyuknow

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

Here are the following Electron Configurations of Phospohorus

1. 1s2 2s2 2p6 3s1 3p4
2. 1s3 2s3 2p6 3s2 3p1
3. 1s2 2s2 2p6 3s2 3p2 3d1
4. 1s2 2s2 2p6 3s2 2d1 3p2
5. 1s2 1p6 2s2 2p5
6. 1s2 2s2 2p6 3s2 3p3

Questions:
Which of these have non-existent orbitals?
Which of these violate Pauli's Principle?
Which of these are in the excited state?
Which of these are it's ground state?

. The attempt at a solution

Just double checking... since I want to get the full marks remaining for this question (got it wrong before, and it's allocated me a new element)

Non-Existent Orbitals
4 & 5, No such thing as 2d and 1p orbitals.
6 is its ground state
1 & 3 are excited states, (the 3s orbitals aren't totally filled?)
That leaves, 2, violating Pauli's principle, which honestly, I have no idea about.

Could someone confirm these for me and perhaps enlighten me more on these.

Thanks!

2. Mar 21, 2013

### Staff: Mentor

What does Pauli's principle say?

(check your notes, or book, or google, or check wikipedia if you don't know)

3. Mar 21, 2013

### nobodyuknow

Pauli's Exclusion Principle...

each electron in an atom has a unique set of quantum numbers which must abide to a specific criteria...

where basically, any orbital can only contain a maximum of two electrons.

Ahh, when I actually bother to read my notes, I see that p-orbitals have 3 sub-orbitals and that s-orbitals contain 1.

So clearly, '2' violates Pauli's Exclusion Law.

However, in my notes, I see that I've got Quantum Numbers noted down, what exactly do these suggest? I can't seem to find my notes on these.

4. Mar 21, 2013

### Staff: Mentor

I don't see what you mean by

Note: name 'orbital' can be confusing, as it used to refer to both p (three suborbitals) and px (or py, pz) - which were just called suborbitals moment ago.

5. Mar 21, 2013

### nobodyuknow

Basically, this 1s3 2s3 2p6 3s2 3p1 violates Pauli's Law because of the third electron in the 2s orbital.

6. Mar 21, 2013

### Staff: Mentor

And 1s3 is OK?