Quantum Numbers Activity

Quantum Numbers

• Quantum numbers tell us properties of the atomic orbitals, and electrons, in an atom.

• Like giving each electron its own addres

• An orbital is a 3-D region of an atom where there is a high probability of finding electrons (NOT an actual ring & NOT like the planetary orbitals)

Principal Quantum Number

Angular Momentum Quantum Number

Magnetic Quantum Number

Spin Quantum Number

Textbook

• You will need a textbook to look up information about the quantum numbers. Pg. 101.

Know for each Quantum #• Definition• Symbol• The allowed values• An example• A visual representation of the quantum number

Review Quantum Numbers as a Class

Discussion of the 4 types of quantum numbers and there properties

Quantum Number Review Notes

Quantum Numbers

• Used to describe various properties of the orbitals

• Each electron is assigned a set of four quantum numbers which, in order, are n, l, ml , and ms

• Like giving each electron its own address

Principle quantum number

• Definition: indicates the main energy level occupied by the electron

• Symbol: n• Values: (written as integers) 1,2,3,4,5,6,7

Angular Momentum Quantum Numbers• Definition: indicates the shape of the orbital• Symbol: l• Values: – 0 = s– 1 = p– 2 = d– 3 = f

• For a specific energy level, the number of orbital shapes available is equal to n -1

Magnetic Quantum Numbers

• Definition: represents the orientation of an orbital around the nucleus

• Symbol: ml

• Values: for a p-orbital -1, 0 , 1

Spin Quantum Numbers

• Definition: represents the spin states of electrons in an orbital

• Symbol: ms

• Values: +1/2, - ½

Can an e- be described by the following set of quantum numbers?

n=2, l=1, ml= -1

All quantum numbers are allowed values

Can an e- be described by the following set of quantum numbers?

n=1, l=1, ml= +1

Not possible.The value of l must be less than the valueof n.

Can an e- be described by the following set of quantum numbers?

n=7, l=3, ml= +3

All the quantum numbers are allowedvalues.

Can an e- be described by the following set of quantum numbers?

n=3, l=1, ml=-3

Not possible.The value of ml must be in the range

-l to +l

Replace the ? Mark with an appropriate quantum number.

n=3, l=1, ml=?

n=4, l=?, ml=-2

n=?, l=3, ml=?

Can an e- be described by the following set of quantum numbers?

n=2, l=1, ml=-2

n=3, l=2, ml=+2

n=4, l=3, ml=+3

n=5, l=2, ml=+3

Writing Quantum Numbers

• You can identify the quantum numbers for any electron in an element

• Start by writing out the the electron configuration and orbital diagram for the element

• Locate the electron in the orbital diagram that you are solving the quantum number for

• Determine the 4 quantum numbers

Hydrogen’s electron

• Write electron configuration• Draw orbital diagram• n= 1• l= 0• ml= 0

• ms= +1/2

Helium’s second electron

• Write electron configuration• Draw orbital diagram• n= 1• l= 0• ml= 0

• ms= -1/2

Lithium’s third electron

• Write electron configuration• Draw orbital diagram• n= 2• l= 0• ml= 0

• ms= +1/2

Flourine’s 6th electron

• Write electron configuration• Draw orbital diagram• n= 2• l= 1• ml= 0

• ms= +1/2