1.1e Particles in the atom and atomic radius

• Chemistry
• Secondary Education
• Age 12,13

AS Level Chemistry 9701

Topic 1.1 Particles in the atom and atomic radius

29 August 2023

Describe how you feel right now 

using an emoji.

😒🙁😐🙂😃

• define and use the term first ionisation energy, IE1  
• explain that ionisation energies are due to the attraction between the nucleus and the outer electron  
• identify and explain the trends in ionisation energies across a period and down a group of the Periodic Table  

I intend to:

29 August 2023, Tuesday

• explain the factors influencing the ionisation energies of elements in terms of nuclear charge, atomic/ionic radius, shielding by inner shells and sub-shells and spin-pair repulsion  
• construct equations to represent first, second and subsequent ionisation energies  
• identify and explain the variation in successive ionisation energies of an element

I intend to:

29 August 2023, Tuesday

• deduce the electronic configurations of elements using successive ionisation energy data  
• deduce the position of an element in the Periodic Table using successive ionisation energy data.    

I intend to:

29 August 2023, Tuesday

AS Level Chemistry 9701

Topic 1.1 Particles in the atom and atomic radius

29 August 2023

• Write the noble gas electron configurations or shorthand EC of Elements 1 to 36.

Review

29 August 2023, Tuesday

Review

29 August 2023, Tuesday

REMEMBER 💭

The Periodic Table is split up into four main blocks depending on their electronic configuration:

• s-block elements (Have their valence electron(s) in an s-orbital)
• p-block elements (Have their valence electron(s) in a p-orbital)
• d-block elements (Have their valence electron(s) in a d-orbital)
• f-block elements (Have their valence electron(s) in an f-orbital)

Review

29 August 2023, Tuesday

Exemption to the Rule: Electronic configurations

Chromium and Copper have the following electron configurations, which are different to what you may expect:

Cr = [Ar] 3d5 4s1 not  [Ar] 3d4 4s2

Cu = [Ar] 3d10 4s1 not  [Ar] 3d9 4s2

Review

29 August 2023, Tuesday

• Free radical - a species with one or more unpaired electrons.

AS Level Chemistry 9701

Topic 1.1 Particles in the atom and atomic radius

29 August 2023

Is energy needed to remove 

valence electrons?

Yes.

No.

Study this!

29 August 2023, Tuesday

Ca (g)  →  Ca+(g)   +   e-       

          

IE1 = + 590 kJ mol-   @298 K , 101 kPa

WALT: Define and use the term first ionisation energy, IE1 

Study this!

29 August 2023, Tuesday

Ca (g)  →  Ca+(g)   +   e-       

          

IE1 = + 590 kJ mol-   @298 K , 101 kPa

• In a statement form, what does the equation tell you? 

WALT: Define and use the term first ionisation energy, IE1 

Study this!

29 August 2023, Tuesday

Ca (g)  →  Ca+(g)   +   e-       

          

WALT: Define and use the term first ionisation energy, IE1 

• The first ionisation energy of Calcium is the energy required to remove one mole of electrons from one mole of the gaseous Calcium.

docs.google.com

Ionisation Energy

29 August 2023, Tuesday

D E F I N I T I O N

• Ionisation energy - the amount of energy required to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous ions. 
•  measured under standard conditions @298 K , 101 kPa
• unit of measure - kilojoules per mole (kJ mol-)

First Ionisation Energy

29 August 2023, Tuesday

E X A M P L E

• Ca (g) → Ca+(g) + e-         IE1 = + 590 kJ mol-   @298 K , 101 kPa

      

• The first ionisation energy of Calcium is the energy required to remove one mole of electrons from one mole of the gaseous Calcium to form one mole of 1+ ions.

Attractive Force in an atom

29 August 2023, Tuesday

WALT: Explain that ionisation energies are due to the attraction between the nucleus and the outer electron  

Attractive Force in an atom

29 August 2023, Tuesday

• Can you break this attractive force?

WALT: Explain that ionisation energies are due to the attraction between the nucleus and the outer electron  

Attractive Force in an atom

29 August 2023, Tuesday

• Can you break this attractive force?

• ionisation energy

WALT: Explain that ionisation energies are due to the attraction between the nucleus and the outer electron  

• Nuclear charge
• Shielding
• Atomic or ionic radius
• Spin-pair repulsion

Factors affecting the magnitude of ionisation energy

29 August 2023, Tuesday

WALT: Explain the factors influencing the ionisation energies of elements in terms of nuclear charge, atomic/ionic radius, shielding by inner shells and sub-shells and spin-pair repulsion    

• increases with increasing proton number
• stronger attractive force between the protons and electrons
• greater nuclear charge = higher ionisation energy needed

Factor 1- Nuclear charge

29 August 2023, Tuesday

WALT: Explain the factors influencing the ionisation energies of elements in terms of nuclear charge, atomic/ionic radius, shielding by inner shells and sub-shells and spin-pair repulsion    

• more shells = more shielding effect due to inter-electron repulsion
• more shielding = weaker attractive force
• more shielding = requires lower ionisation energy

Factor 2 - Shielding

29 August 2023, Tuesday

WALT: Explain the factors influencing the ionisation energies of elements in terms of nuclear charge, atomic/ionic radius, shielding by inner shells and sub-shells and spin-pair repulsion    

• Which has the most shielding effect?

Which has the most shielding effect?

• larger radius = outer electrons are farther away from the nucleus
• greater distance from the nucleus = weaker attractive force
• weaker attractive force = less ionisation energy needed 

Factor 3 - Atomic or ionic Radius 

29 August 2023, Tuesday

WALT: Explain the factors influencing the ionisation energies of elements in terms of nuclear charge, atomic/ionic radius, shielding by inner shells and sub-shells and spin-pair repulsion    

• Spin-pair repulsion happens when the electron being removed is spin-paired with another electron in the same orbital.
•  Non-spin-paired electrons are more difficult to remove, requiring more ionisation energy.

Factor 4 - Spin-pair repulsion

29 August 2023, Tuesday

WALT: Explain the factors influencing the ionisation energies of elements in terms of nuclear charge, atomic/ionic radius, shielding by inner shells and sub-shells and spin-pair repulsion    

AS Level Chemistry 9701

Topic 1.1 Particles in the atom and atomic radius

29 August 2023

• Using the given chart on the first, second, third, and fourth ionisation energies of elements, construct a bar graph.
• The x-axis is the element in symbol with atomic number, and the y-axis is the first ionisation energy, in kJ mol^-.
• Share your graphs with the class.

Week 4 - Activity A (Paired)

29 August 2023, Tuesday

WALT: Identify and explain the trends in ionisation energies across a period and down a group of the Periodic Table  

Conclusions

29 August 2023, Tuesday

• Ionisation energies show periodicity.

Across a period 

• nuclear charge increases
• atomic radius decreases
• shielding remains constant
• gets harder to remove an electron
• ionisation energy increases

WALT: Identify and explain the trends in ionisation energies across a period and down a group of the Periodic Table  

Conclusions

29 August 2023, Tuesday

Down a group

• nuclear charge increases
• atomic radius increases
• distance from the nucleus increases
• shielding increases
• gets easier to remove an electron
• ionisation energy decreases

WALT: Identify and explain the trends in ionisation energies across a period and down a group of the Periodic Table  

Conclusions

29 August 2023, Tuesday

Sudden decrease in IE

• He to Li
• Ne to Na

Slight decrease in IE

• Be to B
• N to O

WALT: Identify and explain the trends in ionisation energies across a period and down a group of the Periodic Table  

AS Level Chemistry 9701

Topic 1.1 Particles in the atom and atomic radius

29 August 2023

Which is easier to remove?

valence e- from a neutral atom

valence e- from an gaseous ion

Successive ionisation energy of elements

29 August 2023, Tuesday

• increases

WALT: Construct equations to represent first, second and subsequent ionisation energies  

Ca0 (g) → Ca+(g)   +  e-

Ca+(g) → Ca2+(g) + 2e-

Successive ionisation energy of elements

29 August 2023, Tuesday

• increases

WALT: Identify and explain the variation in successive ionisation energies of an element

Successive ionisation energy of elements

29 August 2023, Tuesday

• increases

WALT: Identify and explain the variation in successive ionisation energies of an element

AS Level Chemistry 9701

Topic 1.1 Particles in the atom and atomic radius

29 August 2023

Ionisation Energies and Electronic Configuration

29 August 2023, Tuesday

WALT: Deduce the electronic configurations of elements using successive ionisation energy data  

Successive ionisation data can be used to:

• Predict or confirm the simple electronic configuration of elements
• Confirm the number of electrons in the outer shell of an element
• Deduce the Group an element belongs to the Periodic Table

Ionisation Energies and Electronic Configuration

WALT: Deduce the electronic configurations of elements using successive ionisation energy data

Deduce the position of an element in the Periodic Table using successive ionisation energy data   

Self-Assessment for Learning

29 August 2023, Tuesday

T O  D O:

• Identify two ideas you do not understand quite well in our sessions.
• Ask someone who can explain and write the explanations in your notebook.
• Verify your learning from a classmate by sharing it with the teacher.

AS Level Chemistry 9701

Topic 1.1 Particles in the atom and atomic radius

31 August 2023