Bonding, structure and properties
Three types of bonding explain almost every property you can observe: melting point, conductivity, hardness and solubility.
Lesson overview
What you'll learn in this lesson
Relate atomic structure and bonding to the properties of substances.
Key learning points
- • Ionic bonding
- • Covalent bonding
- • Metals and carbon structures
This lesson at a glance
- 30 minutes
- 19 parts to scroll through
- 4 quick checks
- Marked quiz at the end
- Gentle pace: short sittings with pauses
Words to know
Scroll down — the lesson carries on below
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Part 1 of 19
Visual introductionPicture this
Bonding, structure and properties
Three types of bonding explain almost every property you can observe: melting point, conductivity, hardness and solubility.
In a nutshell
Relate atomic structure and bonding to the properties of substances.
Learning cycle
Part 2 of 19
Learning cycle 1 of 2
Part 1 · Ionic bonding
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 3 of 19
Learn
Ionic bonding
A metal transfers electrons to a non-metal, forming oppositely charged ions held in a giant lattice by strong electrostatic forces. Ionic compounds have high melting points and conduct electricity only when molten or dissolved, because only then are the ions free to move.
Reset break
Part 4 of 19
Pause
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Explore the idea
Part 5 of 19
Learn
Covalent bonding
Non-metal atoms share pairs of electrons. Simple molecular substances have strong covalent bonds inside molecules but weak intermolecular forces between them, so they melt at low temperatures and do not conduct. Giant covalent structures such as diamond and silicon dioxide melt at very high temperatures.
Quick check
Part 6 of 19
Quick check
Part 7 of 19
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Part 8 of 19
Pause
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Learning cycle
Part 9 of 19
Learning cycle 2 of 2
Part 2 · Metals and carbon structures
A short piece of teaching, then a check to make sure it has landed.
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Part 10 of 19
Learn
Metals and carbon structures
Metals are a lattice of positive ions in a sea of delocalised electrons, which explains conduction and malleability; alloys are harder because different-sized atoms disrupt the layers. Graphite conducts because each carbon bonds to three others, leaving one delocalised electron, while diamond's four bonds leave none.
Quick check
Part 11 of 19
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Part 12 of 19
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Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Quick check
Part 13 of 19
Explore the idea
Part 14 of 19
Worked example
Worked answer: explain why graphite conducts electricity but diamond does not (4 marks)
In graphite each carbon atom forms three covalent bonds, leaving one electron per atom delocalised (1). These delocalised electrons are free to move through the layers (1), so they carry charge and graphite conducts. In diamond every carbon forms four covalent bonds (1), so there are no delocalised electrons or free ions available to carry charge and it does not conduct (1).
Challenge round
Part 15 of 19
Game · Sort it
Which of these are true?
Drag each card into the right column. Tap a card first if dragging is fiddly.
True
Not true
Reset break
Part 16 of 19
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Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Challenge round
Part 17 of 19
Game · Recall cards
Ionic compounds conduct when molten because
Card 1 of 4
Mastery quiz
Part 18 of 19
Marked quiz
End of lesson quiz: Bonding, structure and properties
4 questions, marked with the reasoning shown. No timer.
1. Ionic compounds conduct when molten because
2. Simple molecular substances have low melting points because
3. Metals are malleable because
4. Diamond does not conduct because it has
Lesson round-up
Part 19 of 19
Lesson round-up
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