1. Magnetism & Electron Configuration Lab Exercise 3.6.1

2. Standard Notation of Fluorine
Number of electrons
in the sub level 2,2,5
1s2 2s2 2p5
Main Energy Level Numbers 1, 2, 2
Sublevels

3. Shorthand Notation
Use the last noble gas that is located in the periodic table right before the element.
Write the symbol of the noble gas in brackets.
Write the remaining configuration after the brackets.
Ex: Fluorine: [He] 2s2 2p5

4. Condensed ground-state electron configurations in the first three periods.

5. Magnetism & Electron Configuration:
Why is iron magnetic and some metals like copper, nickel, zinc etc are not magnetic?
When electrons are paired together, their opposite spins cancel each other. Therefore, no net magnetic field exists.
Substances with some unpaired electrons will have a net magnetic field and will attract more to an external field.
Materials can be classified as diamagnetic, paramagnetic or ferromagnetic.

6. Diamagnetic all the electron are paired
there is no permanent net magnetic moment
Most elements in the periodic table, including copper, silver, and gold, are diamagnetic.
Example: Zinc
The electron configuration of Znis [Ar] 3d10 4s2. All electrons are paired, and therefore Zn is diamagnetic.
The most common ionized form of zinc, Zn(2+) is also diamagnetic. The electron configuration of Zn(2+) is [Ar] 3d10. All electrons are paired, and therefore the Zn(2+) cation is diamagnetic

7. Have some unpaired electrons
Paramagnetic
Weakly magnetic
Have some unpaired electrons
Examples: magnesium, molybdenum, lithium, and tantalum.

8. exhibit a strong attraction to magnetic fields
Ferromagnetic
Strongly magnetic
exhibit a strong attraction to magnetic fields
have some unpaired electrons so their atoms have a net magnetic moment.

9. Magnetic Properties of Transition Metal Ions
Paramagnetic
substances are attracted by an external magnetic field.
Diamagnetic
Species with all paired e’s, not attracted

10. SAMPLE PROBLEM 8.7
Writing Electron Configurations and Predicting Magnetic Behavior of Transition Metal Ions
PROBLEM:
Use condensed electron configurations to write the reaction for the formation of each transition metal ion, and predict whether the ion is paramagnetic.
(a) Mn2+(Z = 25)
(b) Cr3+(Z = 24)
(c) Hg2+(Z = 80)
PLAN:
Write the electron configuration and remove electrons starting with ns to match the charge on the ion. If the remaining configuration has unpaired electrons, it is paramagnetic.
SOLUTION:
(a) Mn2+(Z = 25) Mn([Ar]4s23d5) Mn2+ ([Ar] 3d5) + 2e-
paramagnetic
(b) Cr3+(Z = 24) Cr([Ar]4s23d6) Cr3+ ([Ar] 3d5) + 3e-
paramagnetic
(c) Hg2+(Z = 80) Hg([Xe]6s24f145d10) Hg2+ ([Xe] 4f145d10) + 2e-
not paramagnetic (is diamagnetic)

11. # of unpaired electrons
Hund’s rule of maximum multiplicity
“Multiplicity” is a measure of the number of unpaired electrons.
Multiplicity = number of unpaired electrons + 1
# of unpaired electrons
Multiplicity
Common Name 1
singlet 2
doublet 3
triplet 4
quartet
Hund’s rule: Electrons must be placed in the orbitals of a subshell so as to give the maximum total spin.
i.e. put as many unpaired electrons as possible in a subshell to get the most stable arrangement.