Thermal Energy Review Packet
NYS Intermediate Science • Grade 8 Physical Science Unit 2
Morning Work Week 4
Comprehensive Review: Thermal Energy, Phase Changes & Heat Transfer
Student Name:
Class Period:
Science Teacher:
Date Due:
Weekly Study & Practice Roadmap
Day 1
Particle Motion & States of Matter: Kinetic molecular theory, particle spacing, and temperature vs. thermal energy.
Page 2
Day 2
Phase Changes & Energy Dynamics: Six phase transitions, endothermic vs. exothermic processes, and potential energy.
Page 3
Day 3
Heat Transfer Mechanisms: Conduction, convection, and radiation in everyday atmospheric and lab systems.
Page 4
Day 4
Heating & Cooling Curve Mastery: Analyzing plateaus, phase coexistence, and molecular changes during flat regions.
Page 5
Day 5
Lab Scenarios & CER Reasoning: Thermal equilibrium experiments and scientific claim-evidence-reasoning explanations.
Page 6
Review
Cumulative NYS Assessment & Exit Ticket: Standardized practice items, concept synthesis, and graded formative exit checkpoint.
Pages 7–8
Three Fundamental Laws to Keep in Mind All Week
1. Kinetic Theory
All matter is composed of particles in constant motion. Temperature is average kinetic energy.
2. Heat Flow Rule
Thermal energy always travels spontaneously from hotter objects to colder objects.
3. Phase Plateaus
Temperature does not change during a phase transition; energy alters potential bonds.
NYS P-12 Science Learning Standards: MS-PS1-4, MS-PS3-3, MS-PS3-4 Page 1 of 8
Day 1 • Morning Work Name: ______________________ Date: ________
Kinetic Molecular Theory & States of Matter
1. Microscopic Models of Matter
Solid State
- • Arrangement: Tightly packed, regular lattice
- • Motion: Vibrate in fixed positions
- • Attraction: Strong intermolecular forces
- • Shape/Volume: Definite shape & volume
Liquid State
- • Arrangement: Close contact, random/disordered
- • Motion: Slide and flow past one another
- • Attraction: Moderate attractive forces
- • Shape/Volume: Indefinite shape, definite volume
Gas State
- • Arrangement: Far apart, mostly empty space
- • Motion: Fast, random, straight-line
- • Attraction: Extremely weak / negligible
- • Shape/Volume: Indefinite shape & volume
Temperature vs. Thermal Energy:
Temperature is the average kinetic energy of particles in a sample. Thermal Energy is the total kinetic plus potential energy of all particles. (A large iceberg has more thermal energy than a boiling cup of tea!)
Morning Practice Problems
1. Complete the comparison table below by describing particle motion and spacing:
| State of Matter | Particle Spacing (Close / Far) | Relative Kinetic Energy (Low/Med/High) |
|---|
| Solid Iron Bolt | | |
| Liquid Water (25°C) | | |
| Water Vapor (110°C) | | |
2. A student places a sealed balloon in a freezer. Using kinetic molecular theory, explain why the balloon shrinks in size:
3. Which sample has a higher average kinetic energy?
Sample A: 500 mL of water at 45°C
Sample B: 50 mL of water at 85°C
Correct Sample: Reason:
Standard: MS-PS1-4 (Develop models of atomic/molecular motion) Page 2 of 8
Day 2 • Morning Work Name: ______________________ Date: ________
Phase Changes & Energy Dynamics
1. The Six Phase Changes of Matter
SOLID Low Energy LIQUID Medium Energy GAS High Energy Melting (+Heat) Freezing (-Heat) Vaporization (+Heat) Condensation (-Heat) Sublimation (+Heat Absorbed) Deposition (-Heat Released)
🔴 Endothermic Changes (Absorbs Energy): Melting, Vaporization, Sublimation 🔵 Exothermic Changes (Releases Energy): Freezing, Condensation, Deposition
Crucial NYS Regents Concept:
When a substance changes phase (e.g. ice melting into water), temperature remains constant! Thermal energy added does not speed up the particles (kinetic energy stays flat). Instead, the energy overcomes intermolecular bonds, increasing potential energy.
Daily Practice Tasks
1. Identify the phase change and determine whether it is Endothermic (absorbing energy) or Exothermic (releasing energy):
a) Dew forming on grass on a cool autumn morning Change: Type:
b) Solid dry ice turning directly into carbon dioxide vapor Change: Type:
c) Molten lava cooling and hardening into solid basalt rock Change: Type:
2. A beaker containing pure water at 100°C continues to boil vigorously over a laboratory Bunsen burner for 10 minutes. A thermometer remains in the boiling water the entire time.
Will the recorded temperature increase, decrease, or stay the same? Explain what is happening to the heat energy being added:
3. Draw particle representations showing the transition of liquid water boiling into steam:
Liquid Water (100°C)
Steam / Gas (100°C)
Standard: MS-PS1-4 (Thermal energy and changes of state) Page 3 of 8
Day 3 • Morning Work Name: ______________________ Date: ________
Heat Transfer: Conduction, Convection & Radiation
1. How Thermal Energy Moves Through the Universe
Conduction
Transfer by Direct Contact. Kinetic energy passes molecule to molecule through collisions. Best in solids (metals).
Ex: Metal spoon in hot soup
Convection
Transfer by Fluid Currents. Heated fluids expand, become less dense, and rise; cooler, denser fluid sinks.
Ex: Boiling water, ocean currents
Radiation
Transfer by EM Waves. Does not require matter or particles! Can travel through the vacuum of outer space.
Ex: Sunlight, campfire warmth
Daily Practice Tasks
1. Heating Water in a Metal Pot over a Campfire:
A B C
Letter A:
Method of heat traveling through empty air from flames to pot exterior.
Letter B:
Method of heat circulating warm and cool water within the pot.
Letter C:
Method of heat traveling through solid metal along the handle.
2. Classify each real-world phenomenon and explain the science:
| Real-World Scenario | Heat Transfer Method | Key Evidence / Reasoning |
|---|
| A lizard warms itself by sitting on a flat sun-baked rock | | Direct physical contact |
| Hot air balloon rises when the burner is ignited | | Density change in fluid |
| You feel the heat of asphalt parking lots through shoe soles | | |
3. Why does a thermos flask have a vacuum layer between its inner and outer walls? Which heat transfer method(s) does a vacuum completely stop?
Standard: MS-PS3-3 (Apply scientific principles to design/evaluate thermal devices) Page 4 of 8
Day 4 • Morning Work Name: ______________________ Date: ________
Heating & Cooling Curve Mastery
1. Heating Curve of Pure Water at 1 atm
Slanted = Temp Change | Flat = Phase Change
Thermal Energy Added (Time in minutes) → Temperature (°C) → 100°C 0°C -20°C A B C D E Solid (Ice) Melting (S + L) Liquid Water Boiling (L + G) Gas (Steam)
| Segment | State(s) Present | Temperature Change | Kinetic Energy (KE) | Potential Energy (PE) |
|---|
| A, C, E (Slopes) | One single state | Increasing (Rising) | Increasing | Constant |
| B, D (Plateaus) | Two states coexisting | Constant (0 change!) | Constant | Increasing (Bonds broken) |
Daily Practice Tasks
1. Use the heating curve graph above to answer each question:
a) What is the melting point temperature of this substance?
b) What is the boiling point temperature of this substance?
c) Which lettered segment(s) represent a phase change?
d) At letter D, which two phases of matter coexist?
2. Why is plateau D (boiling) much longer than plateau B (melting)?
Hint: Think about how far apart particles must be pulled to separate completely from a liquid into a gas.
3. Cooling Curve Reflection: If this water sample were cooled from 120°C back down to -20°C:
What would happen to the kinetic energy during condensation at 100°C? What happens to potential energy?
Standard: MS-PS1-4 & MS-PS3-4 (Heating curve analysis & thermal properties) Page 5 of 8
Day 5 • Morning Work Name: ______________________ Date: ________
Lab Scenarios & Scientific Reasoning (CER)
Investigation: Reaching Thermal Equilibrium in an Insulated Cup
Students in an 8th-grade science class dropped a 50 g solid copper block heated to 90°C into an insulated calorimeter containing 100 mL of cold tap water at 10°C. They measured the temperature of both the copper block and water every 60 seconds.
| Time (min) | 0 min | 1 min | 2 min | 3 min | 4 min | 5 min |
|---|
| Copper Temp (°C) | 90°C | 52°C | 31°C | 22°C | 18°C | 18°C |
| Water Temp (°C) | 10°C | 13°C | 15°C | 17°C | 18°C | 18°C |
1. Direction of Thermal Flow:
Which substance lost heat energy, and which substance gained it?
Lost: Gained:
2. Thermal Equilibrium Temp:
At what temperature and time was equilibrium reached?
Final Temp: Time:
Constructed Scientific Explanation: Claim • Evidence • Reasoning (CER) NYS ILST Aligned
Guiding Question: "Using kinetic molecular theory, explain why the copper block's temperature dropped while the water's temperature rose, and why neither substance changed temperature after 4 minutes."
Claim (Direct answer to the scientific question):
Evidence (Specific numerical data from the investigation table):
Reasoning (Apply particle collisions, kinetic energy, and heat flow laws):
Standard: MS-PS3-4 (Plan an investigation to determine energy transfer relationships) Page 6 of 8
Weekly Assessment Name: ______________________ Date: ________
NYS Cumulative Review Assessment
Directions: Circle the best answer for Questions 1–4. Answer Question 5 on the lines provided. Total: 25 Points
1. The diagram below shows particles of a substance inside a closed rigid container.
[3 pts]
If thermal energy is removed from this container until a phase change occurs, the particles will:
A) Move faster and spread further apart
B) Move slower and move closer together
C) Stop moving completely
D) Expand and increase in individual mass
2. Heat from an electric heater on the floor warms an entire room primarily through:
[3 pts]
A) Conduction through the hardwood floorboards
B) Convection currents of warm air rising and cool air sinking
C) Radiation waves absorbed only by dark objects
D) Sublimation of moisture particles in the atmosphere
3. Base your answer on the heating curve graph shown below:
[3 pts]
Plateau X
During Plateau X, what is happening to the thermal energy being absorbed?
A) It is converted into kinetic energy, increasing temperature
B) It is destroying matter to create new elements
C) It is overcoming attractive forces between molecules (increasing PE)
D) It is causing the speed of the particles to double
4. An ice cube at 0°C is dropped into a cup of hot chocolate at 70°C. Which statement is scientifically accurate?
[3 pts]
A) "Coldness" flows from the ice cube into the hot chocolate
B) Thermal energy flows from the hot chocolate into the ice cube
C) Thermal energy flows equally in both directions simultaneously
D) Neither object transfers energy because ice does not conduct heat
5. Extended Response: Atmospheric & Molecular Dynamics
[13 pts]
On a humid summer afternoon in Syracuse, NY, droplets of liquid water form on the outside surface of an ice-cold can of lemonade.
a) Name the specific phase change that produced the water droplets on the can:
b) Describe the change in motion and arrangement of the water vapor particles as they touched the cold can:
c) Energy Transfer: Did the water vapor absorb or release thermal energy during this change?
NYS Grade 8 Intermediate Science Standards Practice Exam Page 7 of 8
Weekly Wrap-Up & Assessment Name: ______________________ Date: ________
Weekly Reflection & Summative Exit Ticket
1. Student Self-Assessment Matrix
| Learning Target / Science Objective | 1 - Need Help | 2 - Getting There | 3 - Proficient | 4 - Mastered |
|---|
| I can model particle spacing and motion in solids, liquids, and gases. | | | | |
| I can identify the 6 phase changes and categorize them as endo- or exothermic. | | | | |
| I can distinguish between conduction, convection, and radiation. | | | | |
| I can interpret heating curves and explain why plateaus remain at constant temperature. | | | | |
2. Thermal Science Concept Connection
In the space below, explain how Heat Transfer causes Phase Changes in terms of Particle Motion:
Weekly Exit Ticket Checkpoint (To be turned in)
3 Question Checkpoint
1. Why does sweating cool your body down on a hot day? (Explain using phase change & energy absorption)
2. Match each heat transfer mechanism to its defining characteristic:
Conduction:
Requires direct ______
Convection:
Circulation in ______
Radiation:
Travels through ______
3. On a heating curve, what physical event occurs when the line is flat?
Answer: Does Temp Change? (Yes/No):
Teacher Evaluation:
Weekly Score: _____ / 100 Exit Ticket: _____ / 15 Effort / Completion: [ ✔+ ] [ ✔ ] [ ✔- ]
Comments / Re-teach Target:
NYS Intermediate Science Review • Morning Work Series Page 8 of 8
