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
- 15 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
Watch & discover
Part 1 of 15
Watch first
Bonding, structure and properties
An English teaching video on this topic from Science Workshop. Watch it, then scroll down for the lesson.
In a nutshell
Relate atomic structure and bonding to the properties of substances.
Learning cycle
Part 2 of 15
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 15
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.
Explore the idea
Part 4 of 15
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 5 of 15
Quick check
Ionic compounds conduct when molten because
Quick check
Part 6 of 15
Quick check
Simple molecular substances have low melting points because
Reset break
Part 7 of 15
Pause
That's sitting 1 of 2 done
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.
Learning cycle
Part 8 of 15
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.
Explore the idea
Part 9 of 15
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 10 of 15
Quick check
Metals are malleable because
Quick check
Part 11 of 15
Quick check
Diamond does not conduct because it has
Explore the idea
Part 12 of 15
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 13 of 15
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
Mastery quiz
Part 14 of 15
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 15 of 15
Lesson round-up
Ready when you are
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Luna: 0 out of 4 on the practice checks. Only if you feel up to it — one more?
Ask LunaDo the work
Your written work for this lesson
This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.
Why the school greenhouse failed
A science club grew tomato plants in the school greenhouse. In June the plants grew well: leaves were dark green and the fruit set quickly. In July the club went away for two weeks and left the greenhouse door shut. When they came back, the leaves were curled and pale and most of the fruit had dropped.
The club had a data logger inside. It showed the temperature reached 46 °C on several afternoons and the soil moisture fell close to zero. The club knew photosynthesis needs light, water and carbon dioxide, and that enzymes in a plant work best in a narrow range of temperature. Above that range the enzymes stop working properly.
The club repeated the summer with the door propped open and a water bottle drip on each pot. Temperature peaked at 31 °C and the plants survived.
Written for Good Learning Co.
Reading questions
- Name the variable the club changed the second time, and one variable they kept the same.
- Explain, using the words photosynthesis and enzymes, why the plants were damaged in July.
- Write a conclusion for the club's report, saying how far the evidence supports it.
Method and results
WritingWrite the aim, what you changed, what you measured and what you kept the same, then record your results in a table.
1 page + results table
Conclusion
WritingExplain what your results show and why, using the scientific words from the lesson. Say how you know you can trust them.
6–8 sentences
Labelled diagram
DiagramDraw the apparatus or the process in pencil, label it fully, and photograph it.
1 labelled diagram
Reading and notes
ReadingRead the lesson text again and write the key ideas in your own words.
Half a page of notes
Saved as you type.
Part 1 of 15 · Watch & discover