This packet is everything a parent or guide needs to assess Unit 04 at home — learning targets, the answers that count as correct, the mastery rubric, calibration examples, and a clipboard score sheet. No multiple-choice test: the student shows mastery by measuring gas behavior and reasoning from particle motion to the laws.
By the end of the States of Matter & Gas Laws unit, a student should be able to:
Six criteria, each judged Not yet / Approaching / Mastered (Page 3).
Measure P, V, and T; plot the data; verify a law.
The student explains behavior from particle motion (Page 4).
Data, plot, and the verified law kept distinct.
You are making a decision, not adding up points. For each criterion, decide whether the work is Not yet, Approaching, or Mastered — the column language tells you which. A criterion counts as mastered only when the student can both take the measurement and justify it from theory. A student carries three tokens per term; one token buys a re-do of one criterion on another day, so a single bad afternoon never sinks the unit.
Accept any answer in the synonyms column — they are pre-approved as equivalent. The third column flags the confusions that look close but are not yet, so you can coach precisely.
| Canonical answer | Accepted synonyms | Common confusion / discriminator |
|---|---|---|
| Gas behavior | ||
| Kinetic molecular theory | KMT; particle model | Pressure comes from particle collisions, not from the gas “pushing” |
| Ideal gas law | PV = nRT | Use absolute temperature (K); real gases deviate at high P / low T |
| Absolute temperature | kelvin scale | Always K in gas laws; never °C in PV = nRT |
| Phase & forces | ||
| Latent heat | heat of fusion / vaporization | Temperature stays constant during a phase change |
| Heating curve | temperature-vs-heat graph | Plateaus = phase changes; sloped parts = warming one phase |
| Intermolecular force | IMF; London / dipole / H-bond | Between molecules, not the bonds within them |
| Hydrogen bonding | H-bond | A strong IMF, not an actual covalent bond |
| Volatility | ease of evaporation | Higher with weaker IMFs; lower boiling point |
| Criterion | Not yet | Approaching | Mastered |
|---|---|---|---|
| Kinetic molecular theory | Describes gases without reference to particle motion. | States the postulates but cannot apply them to behavior. | Uses KMT to explain pressure, temperature, and why real gases deviate from ideal. |
| Gas laws & the ideal gas equation | Plugs numbers into the wrong law or wrong units. | Uses single-variable laws but fumbles PV = nRT. | Selects and applies the correct gas law, tracking units and absolute temperature throughout. |
| Phase changes & energy | Thinks temperature always rises as heat is added. | Names the phase changes but ignores latent heat plateaus. | Reads a heating curve, accounts for latent heat, and explains constant T during a transition. |
| Intermolecular forces | Confuses intermolecular forces with chemical bonds. | Lists the force types but ranks their strength inconsistently. | Identifies dominant forces and uses them to predict boiling point, viscosity, and volatility. |
| Lab technique (gas / pressure measurement) | Misreads the gauge or loses gas to leaks. | Collects data but mishandles temperature or pressure correction. | Measures gas behavior accurately and verifies a gas law against collected data. |
| Integration (cross-domain) | Treats the science as isolated facts; makes no cross-domain connection. | Names a link to history, reading, or writing but cannot defend why it matters. | Connects the unit to its anchor across History · Reading · Writing (plus chosen electives) and defends why the connection matters. |
The split between Approaching and Mastered is theory behind the number: not just plugging into PV = nRT, but explaining why warming a gas raises its pressure. Listen for “the particles hit harder and more often.”
Read these before you grade. They show what Mastered and Not yet actually sound like, plus the edge cases where you should coach rather than decide on the spot.
Student: ______________________________________ Date: _______________ Guide: _________________________
| # | Criterion | Decision | Notes |
|---|---|---|---|
| 1 | Kinetic molecular theory | NY / Appr / Mast | |
| 2 | Gas laws & the ideal gas equation | NY / Appr / Mast | |
| 3 | Phase changes & energy | NY / Appr / Mast | |
| 4 | Intermolecular forces | NY / Appr / Mast | |
| 5 | Lab technique (gas / pressure measurement) | NY / Appr / Mast | |
| 6 | Integration (cross-domain) | NY / Appr / Mast |
☐ No ☐ Yes — for criterion: __________ Tokens remaining: ☐ 3 ☐ 2 ☐ 1 ☐ 0
NY = Not yet · Appr = Approaching · Mast = Mastered · Unsure between two levels? Circle the lower one and note what a re-do would need.