Quantum Electron Model Chapter 5 Mr. Hines

Part A - INTRODUCTION TO THE QUANTUM ELECTRON MODEL

1 Recall basic knowledge from chapter 4 – energy levels, valence electrons, periods, and groups

2 Describe atoms using 2 dimensional space and 3 dimensional space.

3 Explain the spatial orientation of electrons as orbitals.

4 Distinguish between the different types/shapes of orbitals.

5 Determine the maximum number of electrons that each orbital can hold.

6 Speak and write common terminology – Coefficient, character, superscript

Part B – ADVANCED QUANTUM ELECTRON MODEL

7 Define the 2 methods for describing electron orbitals.

8 Define the 3 rules for writing electron configurations and orbital diagrams.

9 Write electron configurations and use shortcuts.

10 Write electron orbital diagrams.

11 Write the arrow diagram for electron structure.

12 Identify s, p, d, and f blocks on the periodic table.

13 Explain why the f block is located below the d block on a traditional periodic table.

14 Compare the quantum model of electrons to the classical model of the electrons.

15 Describe electrons in ground state compared to excited state.

16 Explain the what causes light (and the different colors of light)

PART A – INTRODUCTION TO THE QUANTUM ELECTRON MODEL

Vocabulary Parts C and D

Electron Nucleus Energy level Period Group horse

3-D Emit Orbital S orbital P orbital D orbital

Electron

configuration

Valence

electron

Spacial

orientation

Pauli exclusion

principle

Quantum

model

Coordinate

system

Opposite spin Ground state Excited state Light Electricity color

Superscript Coefficient Element Stable Noble gas 2-D

Quantum model Space calculator Location Coefficient Character

Superscript Clockwise Counterclockwise Proton Heat Mass

Sun Star Orbital diagram spin Hund’s rule Aufbau principle

Target 1- Recall basic knowledge from chapter 4 – energy levels, valence

electrons, periods, groups.

A. Electrons are found around the nucleus in 7 energy levels.

B. Each energy level can hold a certain amount of electrons before filled.

C. An element’s number of energy levels is equal to its period number.

D. The electrons in the outer most energy level of an element are called valence electrons.

E. An element’s number of valence electrons is equal to its group number.

Questions

1. How many energy levels does Phosphorus have? ________

2. How many valence electrons does Phosphorus have? _________

3. What Period is Phosphorus in? _______

4. What Group is Phosphorus in? _______

5. What is the pattern? _______________________________________________________

Target 2 - Describe the 3-dimensional model of the atom using the x, y, z axes.

A. So far we have used models of atoms in 2 dimensions (flat 2-D)

B. The real story of atoms is more complex and requires 3 dimensions (volumetric – 3D)

C. The quantum model of electrons requires 3 dimensions. Pg 131

D. To discuss 3-D space, we need a 3 coordinate system.

E. These coordinate systems are known as x, y, z axes.

Target 3 - Explain the spatial orientation of electrons as orbitals. A. Electrons exist in energy levels around the nucleus. Pg 131

B. Within the energy levels, electrons will occupy a specific space.

C. The 3-Dimensional space where electrons exist is called an orbital.

D. An orbital is the location in space around the nucleus where electrons exist.

E. These orbitals have different shapes and names.

F. An orbital’s shape describes the location of the specific electrons.

Target 4 - Distinguish between the different types/shapes of orbitals. A. Orbitals are specific locations around the nucleus where electrons exist; orbitals can have different

shapes.

B. The first orbital is the “s” orbital and is spherical (round).

C. The second orbital is the “p” orbital and these are dumbbell shaped.

D. The third orbital is the “d” orbital and these are balloon shaped.

E. The forth orbital is the “f” orbital and these are irregular in shape.

Orbital notes

Dog on chain

Questions

1. What is an orbital? _________________________________________________________

2. What does an orbital shape describe? ____________________________________________

3. What is the shape of an “s” orbital? _________________________

4. What is the shape of a “p” orbital? __________________________

5. What is the shape of a “d” orbital? __________________________

s orbitals p orbitals d orbitals

f orbitals - The seven f orbitals are not understood well enough to have agreement on their orientation in space. Their

directional characteristics are too complex to be shown – and are therefore not part of this course.

Target 5 - Determine the maximum number of electrons that each orbital can

hold. Remove answers for student version

Each orbital can only hold a certain amount of electrons.

Orbital Maximum electrons held

s 2

p 6

d 10

f 14

Target 6 - Speak and write common terminology – Coefficient, character,

superscript

1. Coefficient – a number or quantity placed (generally) before and multiplying another quantity

2. Character – a symbol (as a letter or number) that represents information; represents the orbital type for

this section

3. Example - 2S – 2 is the coefficient of S 4. Superscript – A number that is written above and to the right of a character.

5. Example – S2 - 2 is the superscript of S

Practice – Complete the chart

Character Coefficient Write it Character Superscript Write it

S 3 S 3

P 2 P 2

D 4 D 4

a 5.5 a 5.5

Questions

1. What is a coefficient? _______________________________________________

2. What is a character? ________________________________________________

3. What is a superscript? _______________________________________________

Part B – ADVANCED QUANTUM ELECTRON MODEL

Target 7 – Define the 2 methods for describing electron orbitals. A. Since electrons are difficult to keep track of, 2 different systems for describing their locations have

been developed.

1. Electron configurations - notation used to explain the arrangement of electrons in 3-D

2. Orbital diagrams – notation used to explain the arrangement and spin of electrons

Target 8 – Define the 3 rules for writing electron configurations and orbital

diagrams. A. There are 3 rules for writing electron configurations and orbital diagrams. Pg 133

1. Aufbau principle – Electrons occupy the orbitals of lowest energy first.

2. Pauli exclusion principle – Only 2 electrons may

occupy a single orbital at one time. This is only

possible if the 2 electrons have opposite spins***

3. Hund’s rule – electrons will enter each orbital 1 at a time until each orbital contains 1

electron. Only then can a second electron enter the same orbital.

***spin – electrons not only revolve around the nucleus, but they spin on an axis similar to the earth spinning as

it revolves around the sun. Opposite spin just means that 2 electrons will spin in opposite directions (clockwise

and counter-clockwise) pg 134

Target 9 - Write electron configurations and use shortcuts.

Visit these websites for more practice:

These don’t work anymore – look for new ones.

http://intro.chem.okstate.edu/WorkshopFolder/Electronconfnew.html

http://www.chemcollective.org/applets/pertable.php

Complete the chart - pg 133

Element Electron configuration Short cut Electron Configuration

H

He

Li

Be

B

C

N

O

F

Ne

Na

Mg

Al

Si

P

S

Cl

Ar

K

Ca

Sc

Ti

V

Cr

Mn

Fe

Target 10 - Write electron orbital diagrams Element Electron configuration Orbital Diagrams

H

1s1

He 1s2

Li

1s2 2s1

Be 1s2 2s2

B

1s2 2s2 2p1

C 1s2 2s2 2p2

N

1s2 2s2 2p3

O 1s2 2s2 2p4

F

1s2 2s2 2p5

Ne 1s2 2s2 2p6

Na

1s2 2s2 2p6 3s1

Mg 1s2 2s2 2p6 3s2

Al 1s2 2s2 2p6 3s23p1

Si 1s2 2s2 2p6 3s23p2

P 1s2 2s2 2p6 3s23p3

S 1s2 2s2 2p6 3s23p4

Cl 1s2 2s2 2p6 3s23p5

Ar

1s2 2s2 2p6 3s23p6

K 1s2 2s2 2p6 3s23p64s1

Ca 1s2 2s2 2p6 3s23p64s2

Sc 1s2 2s2 2p6 3s23p64s23d1

Ti 1s2 2s2 2p6 3s23p64s23d2

V 1s2 2s2 2p6 3s23p64s23d3

Cr 1s2 2s2 2p6 3s23p64s23d4

Mn 1s2 2s2 2p6 3s23p64s23d5

Fe 1s2 2s2 2p6 3s23p64s23d6

Target 11 - Write the arrow diagram for electron structure.

A. There are 2 models for the diagram, we will use the model on the left; you

should also be aware of the model to the right.

Target 12 - Identify s, p, d, and f blocks on the periodic table.

Target 13 - Explain why the f block is located below the d block on a

traditional periodic table.

Target 14 - Compare the quantum model of electrons to the classical model of

the electrons.

Summary

Electrons occupy a large amount of space around the nucleus of an atom. Electrons are organized

in energy levels and orbitals (where the electrons are located). Since atoms are 3 dimensional, we must

account for all space around the nucleus. When we bring in 3-D, the locations of electrons takes on a

shape – these shapes have names (s, p, d, f). To help keep track of all of the electrons, we write out

electron configurations and orbital diagrams.

Target 15 - Describe electrons in ground state compared to excited state.

1. So far, we have been talking about electrons around the nucleus that are highly organized.

2. When energy is added to atoms such as electricity or heat, the electrons will jump to a higher energy

level.

3. When this happens, all bets are off and the organization of the electrons becomes enormously

complex and is not part of this course.

4. When this happens, we say that the electrons are in an EXCITED STATE.

5. Electrons will NOT stay in excited state for long and will fall back to GROUND STATE.

6. Ground state describes electrons when they are in their normal organized positions.

Notes box – ground state and excited state

Questions

1. What is meant by ground state? _____________________________________

2. What is meant by excited state? _____________________________________

Target 16 - Explain what causes light (and the different colors of light)

a. Light is a form of energy that is released from atoms when electrons fall from excited state to

ground state

b. Right now in the lights in this room, electricity is forcing electrons to the excited state.

c.When the electrons fall back to ground state, the light is emitted which enables you to see.

d. Different atoms will emit different colors of light.

e. When we see things of different color, we are seeing the different forms of electron light

emissions from different elements.

f. This is how we know what our sun is made of and objects in space such as stars.

Use this later for a practice sheet.