Chemistry • Year 11 • Module 1 • Lesson 20
Module 1 Synthesis and Review
Recall and lock in the key vocabulary, concepts and relationships across all three Module 1 inquiry questions before tackling harder application tasks.
1. Term–definition match
The definitions below are shuffled. In the right-hand column write the matching term from this list: ionic bonding, covalent network solid, metallic bonding, dispersion forces, hydrogen bonding, electronegativity, ionisation energy, atomic radius, homogeneous mixture, heterogeneous mixture. 10 marks (1 each)
| # | Definition | Matching term |
|---|---|---|
| 1.1 | The electrostatic attraction between oppositely charged ions formed by electron transfer from a metal to a non-metal. | |
| 1.2 | A solid in which atoms are joined throughout by a continuous lattice of covalent bonds, giving very high melting points and extreme hardness. | |
| 1.3 | The bonding in metals resulting from positive metal ions (cations) surrounded by a “sea” of delocalised electrons. | |
| 1.4 | The weakest type of intermolecular force, arising from temporary dipoles caused by electron motion; present in all molecules. | |
| 1.5 | The strongest type of intermolecular force, occurring between molecules containing N–H, O–H or F–H bonds. | |
| 1.6 | The ability of an atom in a molecule to attract the shared bonding electrons towards itself; increases across a period and decreases down a group. | |
| 1.7 | The minimum energy required to remove one mole of electrons from one mole of neutral gaseous atoms in their ground state. | |
| 1.8 | The distance from the nucleus to the outermost electron shell; decreases across a period and increases down a group. | |
| 1.9 | A mixture that has uniform composition and appears as a single phase throughout (e.g. seawater, air). | |
| 1.10 | A mixture that has non-uniform composition with visibly distinct regions or phases (e.g. sand and water, oil and water). |
2. True or false — with correction
Circle T or F for each statement. If the statement is false, write the corrected version on the line below it. 12 marks (1 T/F + 1 correction each)
2.1 Diamond and graphite are both forms of pure carbon with identical physical properties because they share the same molecular formula. T / F
2.2 Ionic compounds conduct electricity as a solid because their ions are free to move. T / F
2.3 Covalent molecular compounds generally have low melting points because the covalent bonds between atoms are weak. T / F
2.4 Electronegativity increases from left to right across a period because the effective nuclear charge (Zeff) increases while the number of electron shells stays the same. T / F
2.5 Distillation is used to separate components based on differences in their particle size. T / F
2.6 The electron configuration of carbon ([He]2s²2p²) means it has four valence electrons and preferentially forms covalent bonds rather than ionic bonds. T / F
3. Fill-in-the-blank paragraph — the Module 1 framework
Use the word bank to complete the passage. Each word is used once. 8 marks (1 per blank)
Word bank:
atomic number · bonding · covalent network · delocalised · electron configuration · intermolecular · properties · separation
In Module 1, the central framework is: structure determines ___________. The starting point of this chain is ___________, which is determined by the ___________ of the element. The arrangement of electrons determines the type of ___________ that forms between atoms. In metallic substances, ___________ electrons allow electrical conduction and make metals malleable. In ___________ solids such as diamond and silicon dioxide, atoms are joined by continuous covalent bonds, producing very high melting points. In covalent molecular compounds, it is the ___________ forces between molecules (not the intramolecular bonds) that determine melting point. Knowing the physical properties then allows chemists to choose the correct ___________ technique.
4. Function recall
Answer each question in 1–2 sentences using precise chemical terms. 8 marks (2 each)
4.1 What is the function of an electron’s shell number in determining atomic radius?
4.2 Why does graphite conduct electricity but diamond does not, given that both are pure carbon?
4.3 What is the role of electronegativity difference in determining whether a bond between two atoms is ionic or covalent?
4.4 What physical property difference does crystallisation exploit to separate a dissolved solid from its solvent?
5. Build a concept map — the Module 1 chain
Draw labelled arrows between the six terms below to show how they connect. Each arrow must carry a linking phrase (e.g. “determines”, “explains”, “is exploited by”). Aim for at least 6 labelled arrows. 6 marks (1 per valid labelled arrow)
Supplied terms: atomic structure · electron configuration · bond type · physical properties · periodic trends · separation technique.
6. Separation techniques — match technique to property exploited
Complete the table by writing the physical property exploited and one Australian chemistry example for each technique. 10 marks (1 per cell)
| Technique | Physical property exploited | One Australian chemistry example |
|---|---|---|
| Filtration | ||
| Distillation | ||
| Crystallisation | ||
| Chromatography | ||
| Gravimetric analysis |
Q1 — Term–definition match
1.1 ionic bonding • 1.2 covalent network solid • 1.3 metallic bonding • 1.4 dispersion forces • 1.5 hydrogen bonding • 1.6 electronegativity • 1.7 ionisation energy • 1.8 atomic radius • 1.9 homogeneous mixture • 1.10 heterogeneous mixture.
Q2 — True / false with correction
2.1 False. Diamond and graphite are both pure carbon but have entirely different physical properties because their structures are different. Diamond has a 3D tetrahedral covalent network (hard, non-conductor); graphite has layered hexagonal sheets (soft, conductor). Same element, different structure, different properties.
2.2 False. Ionic compounds do not conduct electricity as solids because the ions are fixed in the crystal lattice and cannot move. They conduct only when molten or dissolved in water, where the ions are free to move.
2.3 False. Covalent molecular compounds have low melting points because the intermolecular forces between molecules are weak, not because the covalent bonds within each molecule are weak. The intramolecular covalent bonds are actually quite strong.
2.4 True.
2.5 False. Distillation separates components based on differences in their boiling points (not particle size). Filtration is the technique that uses particle size differences.
2.6 True.
Q3 — Cloze paragraph
In order: properties / electron configuration / atomic number / bonding / delocalised / covalent network / intermolecular / separation.
Q4.1 — Shell number and atomic radius
Each additional electron shell increases the distance from the nucleus to the outermost electrons, so atomic radius increases as the principal quantum number (shell number) increases. Down a group, each successive element has one more electron shell, so radius increases.
Q4.2 — Graphite conducts, diamond does not
In graphite, each carbon uses only three of its four valence electrons in covalent bonds within hexagonal layers, leaving one electron per carbon atom delocalised across the entire layer. These mobile electrons carry electrical charge. In diamond, all four valence electrons are used in covalent bonds to four neighbouring carbons, leaving no free electrons to carry charge.
Q4.3 — Electronegativity difference and bond type
A large electronegativity difference between two bonded atoms (typically > 1.7) indicates ionic bonding: the more electronegative atom strips an electron from the less electronegative atom. A small difference (< 1.7, approximately) indicates covalent bonding, where electrons are shared (equally in non-polar covalent or unequally in polar covalent bonds).
Q4.4 — What crystallisation exploits
Crystallisation exploits the difference in the solubility of a solid in a solvent at different temperatures. The solid is dissolved at high temperature, then the solution is cooled; the solid’s reduced solubility at lower temperature causes it to crystallise out, separating it from more soluble impurities that remain in solution.
Q5 — Sample concept map
Correct maps should include arrows such as:
- atomic structure — determines → electron configuration
- electron configuration — determines → bond type
- electron configuration — determines → periodic trends
- bond type — determines → physical properties
- physical properties — is exploited by → separation technique
- periodic trends — explains → bond type
Award 1 mark per valid labelled arrow. Any scientifically correct linking phrase is acceptable.
Q6 — Separation techniques
Filtration: Particle size (larger insoluble particles are retained by filter paper, smaller solvent particles pass through). Example: removing undissolved impurities from a salt solution in a school laboratory, or separating gravel from water in water treatment plants.
Distillation: Boiling point difference. Example: separation of crude oil fractions at Australian refineries (e.g. Lytton refinery in Queensland); or producing pure water from seawater by distillation.
Crystallisation: Difference in solubility at different temperatures. Example: obtaining table salt (NaCl) from Australian salt lakes (e.g. Lake Gairdner, South Australia) by evaporation/cooling of brine.
Chromatography: Differential distribution between stationary and mobile phases (different affinities for each phase). Example: identifying dyes in Australian food-colouring standards, or forensic analysis of substances.
Gravimetric analysis: Mass of a precipitate formed with known stoichiometry. Example: testing water quality for sulfate ions by precipitating BaSO4 with barium chloride solution.
Accept any valid Australian examples; award 1 mark for the property and 1 mark for a valid example per row.