Electron Configuration and Quantum Numbers

A Look Inside the Atom

Quantum Numbers• n – the principal energy level (size of the

electron cloud) n= 1 to 7• l – azimuthal – sublevels s,p,d,f these are the

regions where the various orbitals exist for the electrons.

• m – magnetic – this reflects the orbitals direction in space.

• s – spin – Pauli Principle states that two electrons sharing an orbital must have opposite spins.

n the energy levels

• There are seven possible energy levels in an atom. Each energy level is larger than the previous, so large that they begin to overlap each other.

• The first energy level to overlap is the 3rd energy level which overlaps energy level 4. Energy level 4 is so large it overlaps into both energy levels 5 and 6! (5,6,7 all follow a similar pattern to energy level 4)

l azimuthal (sublevels) • As energy levels become larger they have more

“compartments” called orbitals. An orbital is the pathway on which electrons travel. The orbitals exist in 4 types:

Sublevel Number of Orbitals Present

Maximum Number of

Electrons Held

Shape of Orbital

S 1 2 Sphere

P 3 6 Infinity sign

d 5 10 ------

f 7 14 ------

m magnetic• Magnetic refers the orbitals direction in space.

Rather than refer to N, S, E or W. We use the axis x, y, and z. (Z axis is actually facing toward you, but we will draw it at an angle to show it.) You will need to be able to draw s and p orbitals, and record their numeric values. The d and f orbitals are very complicated and we will not draw them.

S orbitals value = 0 P orbitals = -1 (px) 0 (py) 1 (pz)

d orbitals have values of -2, -1, 0, 1, 2 f orbitals have values of -3,-2,-1,0,1,2,3

Illustrations of All sublevels, butRemember thatYou only have to Illustrate s and p.

s spin

• refers to the direction of the spin of the two electrons sharing an orbital. According to the Pauli Principle the spin must be in opposite directions. We can record this in two possible manners:

Or +1/2 (one positive spin out of two)and -1/2 (one negative spin out of two)

Summary Tablen l

Possible values

# of orbitals present

maximum# of electrons per

sublevel

Maximum # of electrons for the

energy level

1

2

3

4(5,6,7)

Fill in the information for the sublevels, please wait to go to the next slide until everyoneHas filled in the second column.

Summary Tablen l

Possible values

# of orbitals present

maximum# of electrons per

sublevel

Maximum # of electrons for the

energy level

1 S (0)

2 S (0)P (-1,0,1)

3 S (0)P (-1,0,1)

d (-2,-1,0,1,2)4

(5,6,7)S (0)

P (-1,0,1)d (-2,-1,0,1,2)

f (-3,-2,-1,0,1,2,3)

Please record the number of orbitals present per sublevel. Please wait to flip to nextSlide until after each student has filled in column #3.

Summary Tablen l

Possible values

# of orbitals present

maximum# of electrons per

sublevel

Maximum # of electrons for the

energy level

1 S (0) 1

2 S (0)P (-1,0,1)

13

3 S (0)P (-1,0,1)

d (-2,-1,0,1,2)

135

4(5,6,7)

S (0)P (-1,0,1)

d (-2,-1,0,1,2)f (-3,-2,-1,0,1,2,3)

1357

Please record the number of electrons present per sublevel. Please wait to flip to nextSlide until after each student has filled in column #4.

Summary Tablen l

Possible values

# of orbitals present

maximum# of electrons per

sublevel

Maximum # of electrons for the

energy level

1 S (0) 1 2

2 S (0)P (-1,0,1)

13

26

3 S (0)P (-1,0,1)

d (-2,-1,0,1,2)

135

26

104

(5,6,7)S (0)

P (-1,0,1)d (-2,-1,0,1,2)

f (-3,-2,-1,0,1,2,3)

1357

26

1014

Please record the number of electrons present per sublevel. Please wait to flip to nextSlide until after each student has filled in column #5.

Summary Tablen l

Possible values

# of orbitals present

maximum# of electrons per

sublevel

Maximum # of electrons for the

energy level

1 S (0) 1 2 2

2 S (0)P (-1,0,1)

13

26

8

3 S (0)P (-1,0,1)

d (-2,-1,0,1,2)

135

26

10

18

4(5,6,7)

S (0)P (-1,0,1)

d (-2,-1,0,1,2)f (-3,-2,-1,0,1,2,3)

1357

26

1014

32

You should be able to recreate this table for yourself – hint! Hint!

Illustrating the overlap of the energy levels.

Please take out the blank copy of the extended periodic table that I gave you last class. You will need to be sure that there is a package of colored pencils, markers or crayons at your table.

IA IIA

IIIA

IVA

VA

VIA

VIIA

VIIIA

You will record the energy level color key here in the openSpace. Remember that energy level is indicated by n = **For the purposes of structure we have moved HeliumBeside Hydrogen.

IA IIA

IIIA

IVA

VA

VIA

VIIA

VIIIA

Each row indicates an energy level, or energy levels.Choose your first color to fill in energy level #1.

n=1 your colors don’t have to match mine, but you do need to fill in the same blocks that I do!

IA IIA

IIIA

IVA

VA

VIA

VIIA

VIIIA

Each row indicates an energy level, or energy levels.Choose your next color to fill in energy level #2.

n=1n=2

IA IIA

IIIA

IVA

VA

VIA

VIIA

VIIIA

Each row indicates an energy level, or energy levels.Choose your next color to fill in energy level #3.

n=1 Remember energy level 3 is the firstn=2 to begin to overlap. It will not all ben=3 on the same line.

IA IIA

IIIA

IVA

VA

VIA

VIIA

VIIIA

Each row indicates an energy level, or energy levels.Choose your next color to fill in energy level #4.

n=1 Remember energy level 4 overlapsn=2 two other energy levels. It will not all ben=3 on the same line.n=4

IA IIA

IIIA

IVA

VA

VIA

VIIA

VIIIA

Each row indicates an energy level, or energy levels.Choose your next color to fill in energy level #5.

n=1 n=2 n=3 n=4n=5

IA IIA

IIIA

IVA

VA

VIA

VIIA

VIIIA

Each row indicates an energy level, or energy levels.Choose your next color to fill in energy level #6.

n=1 n=2 n=3 n=4n=5n=6

IA IIA

IIIA

IVA

VA

VIA

VIIA

VIIIA

Each row indicates an energy level, or energy levels.Choose your next color to fill in energy level #6.

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

IA IIA

IIIA

IVA

VA

VIA

VIIA

VIIIA

Now we’re going to indicate which sublevel is representedBy the section of periodic table. The first two columns are s columns, the next 14 are f, the following 10 n=1 are d, and the last 6 are p. n=2 n=3 n=4n=5n=6n=7

IA IIA

IIIA

IVA

VA

VIA

VIIA

VIIIA

s s

p p p p p p

d d d d d d d d d d

f f f f f f f f f f f f f f

Notice that the pattern supports the chart that we created earlier. Using this pattern we can determine the electron configuration for each electron of the atom, n=1 also called the “address” of the electron. n=2 For Hydrogen the electron configuration is: n=3 H 1s¹ the superscript 1 indicates one e¯ in n=1 n=4 Helium would be 1s² indicating 2 e¯ in n=1n=5n=6n=7

Creating Electron ConfigurationStep 1: Locate the desired element on the periodic table. Step 2: Starting with the first row record each position passed over – if an entire section is crossed over the subscript should indicate the number of electrons in the section. For example if you cross over the “p” section record p⁶. The number of the energy level (based on color) would be recorded in front.Step 3: Repeat this process until you reach the position of the desired element.

Follow along with your finger on your colored periodic table as the teacher reads the electron configuration for

Sulfur. S 1s² 2s²2p⁶ 3s²3p⁴

For Zinc:Zn 1s² 2s²2p⁶ 3s²3p⁶ 4s² 3d¹⁰

Now you try:

Complete the electron configuration for each of the following:1. Neon2. Calcium3. Chromium4. Hg

How did you do?

1. Neon 1s² 2s²2p⁶ 2. Calcium 1s² 2s²2p⁶ 3s²3p⁶ 4s²3. Chromium 1s² 2s²2p⁶ 3s²3p⁶ 4s² 3d⁴4. Hg 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶ 6s²4f¹⁴5d¹⁰**If you don’t have the same answers check with your shoulder partner and see if they do, if neither do check at your table. Record any questions for me on Friday.

Record your homework assignment from the board and begin working.

• Homework stamps for today and Friday will be given out on Friday.