CatalystCatalyst1.2.3.
Ways to Organize ShapesWays to Organize Shapes• Organize a sphere on xyz coordinate plane• Organize dumb bells on xyz coordinate plane
Today’s Learning TargetsToday’s Learning Targets• 1.6 – I can characterize an electron based on its 4
quantum numbers (n, l, ml, and ms). I can explain what each of these numbers indicate and discuss the importance of these numbers.
• 1.7 – I can describe the shape, number, and energy level of the s, p, d, and f orbitals. Furthermore, I can draw the s and p orbitals.
• 1.8 – I can write the electron configuration and orbital diagram for any element on the Periodic Table using the Pauli Exclusion Principle and Hund’s Rule.
OrbitalsOrbitals• The solution to the Schrödinger equation gives us
orbitals for a particular element.• Every orbital has a special shape and energy
level.• We keep the idea of energy level (n = 1,2,3, etc.)
from the Bohr model, but remove idea of fixed orbits.
• There are 4 characteristic shapes that an orbital can take.
s Orbitalss Orbitals• Spherical shape• Only one possible orientation around the nucleus.• Seen whenever n (energy level) is 1 or greater
All s orbitals have only one possible
orientation.
p Orbitalsp Orbitals• All p-orbitals are dumb-bell shaped.• Because of the unique shape there are 3 possible
orientations around the nucleus (one along each of the 3 axis).
• Seen whenever n is 2 or greater
d Orbitalsd Orbitals• All d orbitals have a four-leaf clover shape.• 4 possible orientations within the plane and one
odd shape (dz2)
• Appear when n is 3 or higher.
f Orbitalsf Orbitals• These orbitals appear whenever n is 4 or higher• Only seen in elements that have many electrons.
Quick TalkQuick Talk• 1 partner explain s and d orbitals. 1 partner
explain p and f orbitals. Be able to draw s and p orbital
Quantum NumbersQuantum Numbers• We can describe any orbital that an electron
exists in using 4 quantum numbers.• No 2 orbitals can have the same 4 quantum
numbers.• Quantum Numbers:
1. Principal Quantum Number (n)2. Angular Momentum Quantum Number (l)3. Magnetic Quantum Number (ml)
4. Spin Magnetic Quantum Number (ms)
Principal Quantum Number Principal Quantum Number (n)(n)
• Describes the energy level of the orbital• Can have any integer value of 1 or greater (1, 2,
3, etc.)• The bigger n becomes, the higher the energy
level
Angular Momentum ( )Angular Momentum ( )• Describes the shape of our orbital (s, p, d, or f)• Can have any value from 0 to (n – 1)• Each orbital has an assigned angular momentum:
Value of 0 1 2 3
Letter used
s p d f
Quick WriteQuick Write• If I have an element at the n = 3 energy level,
then what type(s) of orbitals do I have?
Magnetic Quantum Number Magnetic Quantum Number (m(m ) )
• ml is any number – to +
• Every orbital can take on a certain number of “allowed” orientations.
• Tells you the number of total electrons an orbital can hold
• The number of allowed orientations is the sum of – to +
Quick WriteQuick Write• How many allowed orientations are there for the s
orbital ( =0)? How many electrons can it hold?• How many allowed orientations are there for the
d orbital ( =2)? How many electrons can it hold?
Spin Magnetic Quantum Spin Magnetic Quantum Number (mNumber (mss))
• Any orbital can contain, at most, 2 electrons• If electrons are in the same orbital, then they
must have opposite spins or ms values
• An electron can either have a spin of +½ or -½
SummarizeSummarize
Around the WorldAround the World
• Around the room there are 10 problems. Cycle through the problems to practice writing electron configurations.
• Complete all problems
5 Minute Break5 Minute Break
Who would perform at Who would perform at the ultimate concert?the ultimate concert?
Concert of a LifetimeConcert of a Lifetime
Concert of a LifetimeConcert of a Lifetime
Stage
Orbitals and their EnergyOrbitals and their Energy• Orbitals, based on many
different reasons, have varying energies.
• n does not determine energy levels when comparing orbitals
Electron Electron
ConfigurationsConfigurations• Electron configurations
describe the distribution of each electron among the various orbitals in the atom
Pauli Exclusion PrinciplePauli Exclusion Principle• Within an atom, no two electrons can have the
same set of 4 quantum numbers.
Orbital Orbital
energy energy
diagramsdiagramsAufbau principle: Build up each atom from the preceding atom by “filling” electrons in from the bottom.
Hund’s RuleHund’s Rule• When placing electrons into a group of similar
orbitals, electrons enter empty orbitals first before they form pairs
Class ExampleClass Example• Draw the electron configuration for fluorine.
Table TalkTable Talk• Draw the electron configuration for magnesium
3 Essential Principles3 Essential Principles1. Pauli Exclusion Principle – Every electron gets its own unique quantum number per element.2. Hund’s Rule – Electrons spread out within the same energy level.3. Aufbau Principle – Fill the lowest energy orbital first
How to Remember Order of How to Remember Order of Orbital FillingOrbital Filling
1s2s3s4s5s6s
2p3p4p5p6p
3d4d5d6d
4f5f6f
Periodic Table Quantum Periodic Table Quantum Shortcut! Shortcut!
• The position of the element determines the last orbital and energy level filled.
Condensed Electron Condensed Electron ConfigurationsConfigurations
• Abbreviate configurations using Noble Gases.• Choose the Noble Gas in the row just above the
element of interest.• Substitute this Noble Gas for all electrons prior to
the row the element is in.
1s22s22p63s23p4 [Ne]3s23p4
10 electrons = Neon!
Class ExampleClass Example• Write the electron configuration for zinc using
condensed notation
Table TalkTable Talk• Write the electron configuration for Tin.
JTPS: Analyze the JTPS: Analyze the ConfigurationConfiguration
• Which configuration for chromium is more stable. WHY?:
1s22s22p63s23p64s23d4 1s22s22p63s23p64s13d5or
Strange Electron Strange Electron ConfigurationsConfigurations
• Due to the closeness in energy of the 3d and 4s orbitals, electrons will spread out in order to satisfy Hund’s Rule.
• Seen most often in chromium and copper.
SummarizeSummarize
Coach and CorrectCoach and Correct
Question 1Question 1• In 3 words or less for each:
o Describe the Pauli Exclusion Principleo Describe Hund’s Ruleo Describe the Aufbau Principle
Question 2Question 2• What is the principal quantum number, number of
electrons, and angular momentum of 5p6
Question 3Question 3• Write the long-form electron configuration for
sulfur
Question 4Question 4• Write the condensed electron configuration for
titanium
Question 5Question 5• Why do electrons fill the lowest energy level first?
Question 6Question 6• Looking at the following electron configurations,
which represents a chemically unreactive element? Justify your answer!
a) 1s____2s ↑ _b) 1s ↑↓ 2s ↑↓_c) 1s ↑↓ 2s ↑↓ 2p ↑ ↑ ____d) 1s ↑↓ 2s ↑↓ 2p ↑↓_ ↑↓ _↑↓_ e) [Ar]4s ↑↓ 3d ↑↓ ↑ ↑ ↑ ↑_
Question 7Question 7• The contour representation of one of the orbitals
for the n = 3 shell of hydrogen atom is shown belowa) What is the quantum number l for this orbital?b) What is the notation for this orbital
Question 8Question 8• An element has a valence shell configuration of
ns2np5, what element(s) is it?
Question 9Question 9• You friend writes the electron configuration for
phosphorus as: [He]3s23p3. What is wrong with the way that they wrote the configuration?
Question 10Question 10• Write the condensed electron configuration for
uranium
Closing TimeClosing Time• You should have all Chapter 6 reading and
homework problems done by Monday/Tuesday to be on track.
• Also, read corresponding chapter in Cracking the AP Chemistry Exam
• Pre-lab for Lab 2 due at start of class Monday/Tuesday.
• No pre-lab = you cannot start lab on time = staying after school to finish the lab.