# Homework Help: Help; physics problem on a chemistry test!

1. Oct 6, 2006

### konartist

So my teacher gave us a take home CHEMISTRY test and I see this problem on it:

What are the azimuthal quantum number (1), magnetic quantum number (m1 ;subscript 1) and spin number for the principle number quantum (n) 3?

I have not a clue how to even start this. I've never even heard of these terms.

I'd really like to tell you guys how I would start this, but I really have no clue.

2. Oct 6, 2006

### moose

or even better, your chem text.

BTW, that's chemistry (well it can be considered chemistry or physics, I suppose?).

3. Oct 6, 2006

### pibomb

Ok...I think this is an explanation

Principle quantum number defines the amount of energy basically gives a first clue of how much energy an electron has. (this entity can take on any integer). Geometrically, this represents the size of an electron shell.

Azimuthal quantum number defines how much angular momentum (amount of momentum around an axis) that an electron has and takes on any value above zero and between n-1 (In this case n=3, therefore, azimuthal, or orbital, quantum number takes on 0,1, and 2). Geometrically, this is the shape of the electron cloud (such as the dumbbell)

Magnetic quantum number is another number related to azimuthal that defines the direction of an electron's angular momentum. This takes all the values between lxl [absolute values of x] of the azimuthal number. (for example, l [azimuthal number] = 2, then the magnetic quantum number is -2, -1, 0, 1, 2). Geometrically, this is the specific area of which the electron clouds are around the atom.

Finally, spin quantum number reflects electron spin (an intrinsic property where an electron "spins" around it's axis). This value can only take on 1/2 or -1/2.

So, this is an explanation for what quantum numbers actually are...to figure out what the numbers are use the laws I gave. So...n=3 and l=1 means that the magnetic number can be -1,0, or 1. For spin number, one needs to know the Pauli Exclusion principle, google this and hopefully my discussion will make more sense (this knowledge is needed to find the spin).

4. Oct 6, 2006

### Mindscrape

Yes, because that is boring physics it is, by definition, known as chemistry.

5. Oct 7, 2006

### junior_J

:rofl: haha thats a little out of line dont u think ?

6. Oct 7, 2006

### pibomb

I think quantum chem is interesting actually...

7. Oct 7, 2006

### konartist

Thanks guys! Your help worked for me.