This lesson contains 48 slides, with interactive quizzes and text slides.
Items in this lesson
AS Level Chemistry 9701
Topic 3 Chemical Bonding
19 September 2023
Slide 1 - Slide
Describe how you feel right now
using an emoji.
πππππ
Slide 2 - Poll
define electronegativity as the power of an atom to attract electrons to itself
explain the factors influencing the electronegativities of the elements in terms of nuclear charge, atomic radius, and shielding by inner shells and sub-shells
state and explain the trends in electronegativity across a period and down a group of the Periodic Table
I intend to:
19 September 2023, Tuesday
Slide 3 - Slide
use the differences in Pauling electronegativity values to predict the formation of ionic and covalent bonds (the presence of covalent character in some ionic compounds will not be assessed) (Pauling electronegativity values will be given where necessary)
define ionic bonding as the electrostatic attraction between oppositely charged ions (positively charged cations and negatively charged anions)
I intend to:
19 September 2023, Tuesday
Slide 4 - Slide
AS Level Chemistry 9701
Topic 3 Chemical Bonding
19 September 2023
Slide 5 - Slide
ability of an atom to attract a pair of electrons towards itself in a covalent bond
Electronegativity
19 September 2023, Tuesday
Slide 6 - Slide
Slide 7 - Slide
positive nucleusβs ability to attract the negatively charged electrons, in the outer shells, toward itself
19 September 2023, Tuesday
Slide 8 - Slide
used to assign a value of electronegativity for each atom
Pauling Scale
19 September 2023, Tuesday
Slide 9 - Slide
Slide 10 - Slide
Which atom is the most electronegative?
Slide 11 - Slide
mostelectronegative atom on the Periodic Table, with a value of 4.0 on the Pauling Scale
Fluorine, F
19 September 2023, Tuesday
Slide 12 - Slide
mostelectronegative atom on the Periodic Table, with a value of 4.0 on the Pauling Scale
Fluorine, F
19 September 2023, Tuesday
What does this tell you?
Slide 13 - Slide
Slide 14 - Slide
AS Level Chemistry 9701
Topic 3 Chemical Bonding
19 September 2023
Slide 15 - Slide
Nuclear charge
Atomic radius
Shielding
Factors affecting electronegativity
19 September 2023, Tuesday
Slide 16 - Slide
Slide 17 - Slide
Slide 18 - Slide
Oxygen
Sulfur
Slide 19 - Drag question
AS Level Chemistry 9701
Topic 3 Chemical Bonding
19 September 2023
Slide 20 - Slide
Electronegativity trends
19 September 2023, Tuesday
Slide 21 - Slide
Slide 22 - Slide
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Slide 24 - Slide
AS Level Chemistry 9701
Topic 3 Chemical Bonding
19 September 2023
Slide 25 - Slide
The differences in Pauling electronegativity values can be used to predict whether a bond is covalent or ionic in character.
Predicting bond formation
19 September 2023, Tuesday
Slide 26 - Slide
Single covalentbonds are formed by sharing a pair of electrons between two atoms.
Covalent bonds
19 September 2023, Tuesday
The equal distribution leads to a non-polar molecule.
Slide 27 - Slide
When atoms of different electronegativities form a molecule, the shared electrons are NOT equally distributed in the bond.
Polar/Nonpolar bonds
19 September 2023, Tuesday
The unequal distribution leads to a polar molecule.
A molecule with partial charges forms as a result
Slide 28 - Slide
The more electronegative atom will have a partial negative charge (delta negative, Ξ΄-).
The less electronegative atom will have a partial positive charge (delta positive, Ξ΄+).
Polar/Nonpolar bonds
19 September 2023, Tuesday
Slide 29 - Slide
Slide 30 - Slide
If there is a large difference in electronegativity of the two atoms in a molecule, the least electronegative atomβs electron will transfer to the other atom.
Ionic bonds
19 September 2023, Tuesday
Slide 31 - Slide
Slide 32 - Slide
Ionic bond β one atom transfers its electron and the other gains that electron
The cation β positively charged species that has lost (an) electron(s).
The anion β negatively charged species that has gained (an) electron(s).
Ionic bonds
19 September 2023, Tuesday
Slide 33 - Slide
Slide 34 - Slide
Identify whether the following forms: simple covalentbond, polar bond, nonpolar bond, or ionic bond.
Sodium chloride
Bromine gas
Carbon dioxide gas
Water molecule
Bonds Practice
19 September 2023, Tuesday
Slide 35 - Slide
AS Level Chemistry 9701
Topic 3 Chemical Bonding
19 September 2023
Slide 36 - Slide
involves the transfer of electrons from a metallic element to a non-metallic element.
Ionic bonding
19 September 2023, Tuesday
Slide 37 - Slide
Once the atoms become ions, their electronic configurations are the same as a stable noble gas.
A potassium ion (K+) has the same electronic configuration as argon: [2,8,8]+
A chloride ion (Cl-) also has the same electronic configuration as argon: [2,8,8]-
Ionic bonding
19 September 2023, Tuesday
Slide 38 - Slide
Slide 39 - Slide
Slide 40 - Slide
Slide 41 - Slide
The ionic bond - electrostatic attraction formed between the oppositely charged ions, which occurs in all directions
This form of attraction is very strong and requires a lot of energy to overcome
This causes high melting points in ionic compounds.
Ionic bonding
19 September 2023, Tuesday
Slide 42 - Slide
Ions in a lattice are arranged in a regular repeating patternso that positive charges cancel out negative charges.
The ions form a lattice structure which is an evenly distributed crystalline structure.
Slide 43 - Slide
The final lattice is overall electrically neutral.
Ionic bonding
19 September 2023, Tuesday
Slide 44 - Slide
Slide 45 - Slide
AS Level Chemistry 9701
Topic 3 Chemical Bonding
19 September 2023
Slide 46 - Slide
Draw the dot-and-cross diagrams to show how these ionic compounds formed.
Sodium chloride
Magnesium oxide
Calcium fluoride
Ionic bonding
19 September 2023, Tuesday
Slide 47 - Slide
Self-Assessment for Learning
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.