# Quantum Numbers for all elements???

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Can any of you please post a link to a periodic table or a list of all the elements and their quantum #'s? I have a Chemistry Final Exam in 2 days, so please post asap.

Thanks.

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There is a very simple pattern to the valence electron configurations of elements in the periodic table:

Now, to begin with.. the 1A and 2A (alklai & alklai earth metals) groups are all have S orbital valence electrons. Now to determine that.. count down to the element you want. Lets say Potassium. It is four 'blocks' down, so thats 4, and because its in the 1A group. its S.. so now its 4S.. and because its the first in the first column it has 1 valence electron. So its 4S1. Now anothe example from lets say the P orbitals.. Nitrogen. Its 2 rows down. so thats 2. Its in the 'p' section (From the periodic table above) so its 2P.. its 3 across.. so its 2P3. Its a very simple pattern and you should get the hang of it very quickly. Good luck on the test!

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I think I have that down, but can you explain the quantum #'s n,l,ml,ms?

Be-would be [HE] 2s^2 but what are the quantum #'s?

What wuld it be (2,0,?,?)

N-[HE] 2s^2 2p^3 (2,1,?,?)

I think i need help with the last 2 quantum #'s ml, and ms.

Thanks a bunch.

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The quantum numbers describe various properties of the orbitals of an atom.

The first being the principle quantum number

It has integral values. (1, 2, 3 etc..) This is related to the size and energy of the orbital. The bigger the integer, the larger the size and the greater the energy of the orbital. This is because the electrons are farther away and less rightly bound to the nucleus.

The second is the angular momentum quantum number (the 'l' )

this has a value from 0 to n - 1 where the principle quantum number is n. This value is related to the shape of the atomic orbitals. This quantum number usually has a letter assigned to each integer. 0 being S, 1 being P, 2 being d etc..

The thrid is the magnetic quantum number (the ml)

this basically has interger values between l and -l (l being the angular momentum quantum number) and this is related to the orientation of the orbital relative to the other orbitals in the atom.

A simpler way would be:

S orbitals take 2 electrons

P orbitals take 6 electrons

D orbitals take 10 electrons

now divide those numbers by half and you have the number of orbitals in each energy level. This is because each orbital can take 2 electrons.

Now one more thing which you would probably have to know is the electron spin (ms) (the fourth quantum number). It is always either +1/2 or -1/2 and it won't be nessicary to know wether is +1/2 and -1/2.. all you have to know is if there are two electrons in an orbital then assign the first a value of potitive 1/2 and the other negative 1/2.

Now regarding Beryllium (Be) it would be [HE] 2s^2. The four quantum numbers would be: (2, 0, 0, 1/2)

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Thanks for all your help. You cleared it up a ton.

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