Angela's Wand Chapter 24 · Unit 8: States of Matter · Segment 3
When thermal energy is added to or removed from a substance, what happens to how its particles move, to its temperature and to its state?
Students figure out that temperature, thermal energy and heat are three different ideas: temperature reports how energetic a sample's particles are on average, thermal energy is the total for all of them, and heat is energy that flows from warmer matter to cooler matter because their temperatures differ. They use a particle model to predict all six changes of state, measure a melting curve and discover that a pure substance stays at one temperature while it changes state, test which cup of water can melt the most ice, and engineer a container that slows the energy flowing into an ice cube. These ideas explain dew, frost, boiling kettles and why farmers spray water on crops on freezing nights.
Estimated class time: presentation about 128 minutes · worksheets about 430 minutes in total · labs 4 sessions. Eight 50-55-minute periods plus homework: one for temperature, thermal energy and heat; one for the melting-curve lab; one for the six state changes; one for the which-cup mystery lab; one for why the temperature holds steady, evaporation versus boiling, attractions and the frost-protection connection; two for the insulation engineering lab; one for the jigsaw, misconception, synthesis and exit. Several worksheets (W3, W5, W7, W9) are designed as homework, and W6 (45 minutes) and W10 (40 minutes) fill one or two following assessment periods. A five-period version can skip Lab 2 (use W5 instead) and run Lab 3 as a single test round.
On a warm, humid afternoon a student sets a can of juice from the refrigerator and a tall glass packed with ice water on a paper towel. Within a minute both turn misty, and soon drops run down their sides and wet the towel, although neither container leaks. A thermometer in the glass, stirred every few minutes, reads 0 °C and stays there for most of an hour while the ice shrinks, even though the room is 27 °C. Only after the last sliver of ice is gone does the reading begin to climb. Where does the water on the outside come from, and why does the ice water stay at 0 °C while energy from the warm room keeps flowing into it?
Notice and wonder prompts
California NGSS, Grade 7 Preferred Integrated Course Model. Each entry says whether this chapter's work assesses the performance expectation, gives practice toward it, or supports it as background; the resource lists below repeat this for every worksheet and lab.
Develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed.
Students build and use particle models of solids, liquids and gases for all six state changes, and in Lab 1 they predict, measure and model a melting curve, drawing what the particles are doing before, during and after melting and explaining why the temperature holds at 0 °C. The chapter stays inside the clarification statement: models are drawings and diagrams, and no task calculates energy.
Plan an investigation to determine the relationships among the energy transferred, the type of matter, the mass, and the change in the average kinetic energy of the particles as measured by the temperature of the sample.
This is a California Grade 6 PE, so seventh graders are revisiting it. Lab 2 (which cup can melt the most ice) and the bath data in Lab 1 lean on its core idea that the energy a sample can transfer depends on its mass as well as its temperature, but students do not plan the full investigation the PE describes, and nothing calculates the total thermal energy transferred.
Assessment boundary: Assessment does not include calculating the total amount of thermal energy transferred.
Apply scientific principles to design, construct, and test a device that either minimizes or maximizes thermal energy transfer.
This is a California Grade 6 PE. Lab 3 revisits it: students design, build and test an insulating container that slows the energy flowing from the room into an ice cube. The chapter treats the lab as practice of the Grade 6 PE in a Grade 7 context, connected to melting as a state change, and does not calculate energy transferred.
Assessment boundary: Assessment does not include calculating the total amount of thermal energy transferred.
Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success.
In Lab 3 groups post their first-round melt data, compare the features of the best and worst designs across the class, and build a second version that combines the most effective characteristics, then retest it. The class data table and the written redesign rationale are direct evidence for this PE.
Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions.
Lab 3 gives students a design brief and asks them to restate its criteria and constraints as measurable targets (percent of ice lost, budget, size, access time) and to name the scientific principle each design choice relies on. The criteria are supplied rather than developed by students, so the role is practice.
Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.
In W9 students score five frost-protection plans for a vineyard against stated criteria and constraints in a decision table, using the test data and the particle model of freezing and evaporation, before recommending one plan. The plans and their results are supplied rather than designed by students, so the role is practice.
Heat, Temperature, and State Changes: where the energy goes. Original, editable slides with speaker notes: a phenomenon opener, learning targets, the chapter's concepts with diagrams, vocabulary in context, 3 checks for understanding, 2 discussion prompts, an application task, a misconception check, a synthesis and an exit ticket.
Ten different tasks, one per instructional blueprint. Each has a student PDF (low ink, US Letter), an editable DOCX, an HTML preview, and a separate teacher answer key with reasoning.
I can record what I notice and wonder about cold containers in a warm room, use what I already know about particles and energy, and write first explanations for where the water on the outside comes from and why ice water stays at 0 °C.
I can tell heat, temperature and thermal energy apart, sort the six changes of state by the energy they need, and use the terms correctly to describe new situations.
I can use evidence from a passage to explain the difference between temperature, thermal energy and heat, and why a substance's temperature stays level while it melts or boils.
I can interpret each part of a heating curve and draw particle models that show how particle motion, temperature and state change as thermal energy is added to or removed from water.
I can graph heating data for two masses of ice, calculate how long each plateau lasts and how fast each temperature rises, and explain the results with a particle model.
I can write a claim-evidence-reasoning argument, using test data and a particle model, that explains where the water on a cold container comes from and why it forms.
I can find the errors in another student's statements and graph about heat, temperature and state changes, name the idea that went wrong, and rewrite each one so it is scientifically accurate.
I can work with my group to compare the melting and boiling points of twelve pure substances, predict each one's state at a given temperature, and explain the pattern with how strongly their particles attract one another.
I can use a particle model of freezing and evaporation to predict how different frost-protection plans change the temperature of grape buds, evaluate the plans against criteria and constraints, and justify a decision.
I can show that I can tell heat, temperature and thermal energy apart, predict which way energy moves, name and model all six changes of state, read a heating curve, and explain why substances change state at different temperatures.
Three different investigation approaches. Each has a teacher guide (purpose, materials with quantities, estimated cost, prep, safety, procedure, expected observations, debrief, answer key, assessment criteria, accessibility adaptations, low-cost alternative) and a student recording sheet.
When a cup of ice sits in a warm bath, energy flows into it the whole time. What happens to the temperature and the particles of the ice while it melts, and after it has melted?
Four covered cups of water look identical from the outside. Which one can melt the most ice, which one holds the most thermal energy, and are those the same question?
How can you use everyday materials to slow the energy flowing from a warm room into an ice cube, so that as little of it as possible melts in 25 minutes?
Materials overview: No flames and no water above 45 °C for students; the teacher prepares any warm water and handles anything hotter than 50 °C. Lab 1 uses crushed ice, a tub of warm tap water, two thermometers per group, plastic cups and spoons. Lab 2 uses lidded foam cups of water prepared at four masses and temperatures, ice, a kitchen scale, thermometers and a strainer. Lab 3 uses small homemade ice pucks, plastic cups, everyday insulating scraps (foil, cotton balls, felt, newspaper, bubble wrap, packing peanuts, cardboard), tape and a 0.1-gram pocket scale. Optional demonstrations: a glass of ice water on a humid day, a steel can of ice and salt that grows frost, and an electric kettle (teacher only) for the boiling-point plateau. Glass thermometers must be alcohol-filled, never mercury.
Review status: reviewed · 2026-10-19 · Verified the earlier link fixes are in place: slides 5 and 10 point to Lab 2, W5 and W3 (not W6); slides 13 and 15 point to W2 for the six-change sort; slide 20 points to the W8 Substance Experts jigsaw; slide 22 points to the W1 revision and the W6 cold-can CER; evidenceOfLearning names W2 and the slide 15 check for the six-change model and W4 for heating-curve particle drawings. Every slide, period and lab cross-reference was checked against the files as written. Added MS-ETS1-2 (caGrade 6-8, practice) to chapter standards and to the ETS1.B dimension, because W9 has students score five frost-protection plans in a decision table; caGrade checked on every standards entry (MS-PS1-4 7; MS-PS3-4 and MS-PS3-3 6, each labeled as a California Grade 6 PE). Science and numbers re-solved: the slide 17 heating curve (1.25 : 8 : 10 minutes) and the W5 dataset (1 : 8 : 10) match water's real ratios for warming ice from −25 or −20 °C, melting and warming the liquid to 100 °C; W4's 0.5 : 2.5 : 3 is approximate and captioned as such. The slide 5 snow figures (0.25 kg and 75 kg) and the slide 23 bath data are consistent. Lab 2's four cups give ideal melts of about 22, 55, 88 and 2 g (W, X, Y, Z), so the Y, X, W, Z ranking holds and every cup keeps leftover ice; the thermal-energy ranking Y, X, Z, W is sound. Frost-protection claims (latent heat released, ice-water coat near 0 °C, run sprinklers until the ice melts, about 3 mm of water per hour) match the FAO guide. Every melting and boiling point checks out at normal pressure. Fixed: the slide 10 notes said a pot of 30 °C water with several times the mug's water melts several times as much ice (it needs more than three times the water just to tie); the W8 q7 premise that air cooled to −190 °C at normal pressure would hold liquid oxygen (real air does not start to liquefy until a little below −191 °C; it now uses two tanks of pure gas); the W6 scenario had students blot the drops before weighing; the Lab 2 teacher notes pointed to the W6 CER as a cup-data follow-up; the W2 q6 key mentioned a 'fuzzy coating' that is not on that sheet; slide 21 now says young salmon and steelhead; the Lab 1 thermometer cost range now matches its own basis. Pacing: Period 1 (slides 1-10 plus W1) and Period 8 (the W8 jigsaw plus slides 24-26) ran past 55 minutes, so the sequence now lets W1 Part C and the exit ticket move to homework or the next class; W6 and W10 together need about 85 minutes, so the plan now allows one or two assessment periods; W9's directions now cover doing it as homework. Originality: no six-word run from the lesson text outside cited section titles. All labs state that they have not been physically tested.
Verified against the student edition of Bring Science Alive! 7th Grade Integrated (Student Edition). Printed page numbers appear in the book; PDF pages are the physical pages of the 524-page scan (printed + 36). The textbook is not reproduced on this site.
| Section | Printed pages | PDF pages | Used for |
|---|---|---|---|
| Introduction: the winter geyser, the lesson question, vocabulary and the NGSS box | 308, 309 | 344, 345 | Lesson question, vocabulary terms, the publisher's standards box and its note that total thermal energy depends on temperature, amount and state (accuracy notes, slide 1). |
| 1. Thermal Energy, Temperature, and Heat | 310, 311 | 346, 347 | Temperature as average kinetic energy, thermal energy depending on the number of particles, heat as energy transferred from warmer to cooler by collisions, equal exchange at the same temperature (slides 4-10, Lab 2). |
| Spread: Comparing Heat, Thermal Energy, and Temperature | 312, 313 | 348, 349 | Two pot sizes at the same temperature with different thermal energy, heat arrows from flame to pot and pot to ice (slide 5 compare diagram; the cooling-panel issue in accuracy notes). |
| 2. Objects Gain Thermal Energy: melting, evaporating, subliming | 314, 315 | 350, 351 | Particle descriptions of melting at 0 °C, evaporation at the surface versus boiling throughout, dry ice subliming (slides 11-16, 19, Lab 1). |
| 3. Objects Lose Thermal Energy: condensing, freezing, depositing | 316, 317 | 352, 353 | Condensation on a cooler lid, freezing as particles lock into place, deposition of frost and the gold-coating example (slides 11-15, 21-22; accuracy notes). |
| Key Science Concept: Gaining or Losing Thermal Energy Causes State Changes | 318 | 354 | The six-arrow model with energy added or removed, rebuilt as the slide 13 map; the steady-temperature gap noted in accuracy notes. |
| 4. Attractions Between Particles | 319 | 355 | Different melting and boiling points from different strengths of attraction, helium versus water (slide 20). |
| Lesson Summary | 319 | 355 | Checking that every summary idea is covered by a target, a slide and a lab; the 'average speed' wording corrected in accuracy notes. |
