Quantum Numbers, N, L, Ml, Ms , And Electron Configuration Summary printable pdf download

Quantum Numbers, n, l, m l , m s , and Electron Configuration Summary

Energy Level or Shell: n , or the Principle Quantum number: distance from the nucleus:

n = 1, 2, 3, 4, 5, 6, 7 ...

higher n is farther from the nucleus

Sublevel or Subshell: s, p, d, f or the Azimuthal quantum number: l = 0, 1, 2, 3.... (l = 0 to n–1)

describes the shape of orbital: s = spherical, p is dumbell, d is double dumbell

Orbital: Magnetic quantum number, m l , =– l to l : Orientation in space of the atomic orbital:

Each type of sublevel (or shape) has different numbers of orbitals

s has 1 orbital p has 3 orbitals: p x , p y , p z

d has 5 orbitals

f has 7 orbitals

Electron: Spin quantum number, m s = +1/2 or –1/2 : Which electron in the orbital?

There can be at most 2 electrons, with opposite spins, in any orbital.

s has 2 electrons

p has 6 electrons

d has 10 electrons

f has 14 electrons

Summary: In an Energy Level: There are n sublevels, n 2 orbitals, and 2n 2 maximum electrons

sublevel m l

l sublevel

m l

l sublevel

m l

–1, 0, 1

–2, –1, 0, 1, 2

-2, -1, 0, 1, 2

-3, -2, -1, 0, 1, 2, 3

Diagonal rule: The energy (and filling order) of the sublevels follows a diagonal pattern. For

example, the 4s is lower energy than, and filled before, the 3d, even though the 4s is farther from

the nucleus than the 3d.

Each row across represents an energy level

The higher in the chart, the farther from the

nucleus the level is.

The s, p, etc. represent sublevels. For

example, “4s” means the s sublevel of the

4th energy level, or n=4, l=0

Notice that the number of sublevels in any

energy level is equal to the principle

quantum number of that level.

(4th energy level has 4 sublevels)

or n = 4, l = 0, 1, 2, 3

These three principles govern the filling order of orbitals by electrons.

1. Aufbau Principle: Electrons enter orbitals of lowest energy first. The diagonals in the above

diagram show this order. The superscripts tell how many electrons can occupy that sublevel.

1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 14 5d 10 6p 6 7s 2 5f 14 6d 10 7p 6 ....

2. Pauli Exclusion Principle: An orbital contains a maximum of two electrons, with opposite spins, or

no two electrons in an atom can have the same set of four quantum numbers.

3. Hund's rule: When electrons occupy orbitals of equal energy (degenerate), one electron enters each

orbital until all the orbitals contain one electron with spins parallel.

Quantum Numbers, N, L, Ml, Ms , And Electron Configuration Summary

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