Name: ________________________________________________________ Class: _________________ Date: ___________________
How Thermal Energy Changes Matter
Learning Goals
By the end of this lesson, I can:
• Explain how adding/removing thermal energy
changes particle motion and state.
• Use temperature data to show how energy
changes a system over time.
• Correctly use the terms heat (energy transfer)
and temperature (average kinetic energy).
Safety & Materials
-
Handle hot water carefully
Keep beakers in the center of benches
No running
Use tongs/gloves for hot items
Wipe spills immediately.
Materials (per group):
- 1 beaker
- Ice
- Warm water
- Thermometer
- Timer
- Paper towels.
Research Question & Hypothesis
Research Question:
How does adding or removing thermal energy change a material’s temperature and state?
Write your hypothesis in a complete sentence using scientific terms (particles, energy in/out, temperature):
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Variables (Identify & Control)
• Independent Variable (IV): ______________________________________________________________
• Dependent Variable (DV): ______________________________________________________________
• Controlled Variables: (Variables that you are KEEPING THE SAME)
- starting volume of water
- starting temperature
- same container
- same thermometer placement
- same measurement intervals.
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Procedure (Follow Step-by-Step)
1. Place ~100 mL of crushed ice into the beaker.
2. Add ~20 mL warm water to make good contact with the thermometer bulb.
3. Record the start temperature (t = 0 min).
4. Measure and record the temperature every 1 minute for 10 minutes while the sample warms gently
(teacher will control any heat source). Do not remove the thermometer.
5. After the warming period, stop heating and allow the beaker to cool.
6. Continue recording temperature every 1 minute for another 10 minutes.
7. Observe and note any physical changes (melting, condensation, small bubbles).
8. Plot your data as you collect it: Time (min) on the x-axis and Temperature (°C) on the y-axis.
9. Label sections of your curve where the sample is solid, melting, and liquid. Mark energy in/out
with arrows.
Data Table (Temperatures Each Minute)
Time (min)
Temperature (°C)
Observations (melting?
condensation?)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
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Data Table (Temperatures Each Minute)
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Analysis – Explain with Particles & Energy
1) When the ice melted, what happened to the temperature on your thermometer?
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2) Why do you think the temperature stayed the same or changed slowly?
(What might the particles be doing as the ice turns to water?)
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3) How could you tell that the ice was gaining heat at the start and losing heat at the end?
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4) How would your curve look different if you started with only liquid water? Why?
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Mini-Task – Heat vs Temperature
Decide whether each statement describes HEAT (energy transfer) or TEMPERATURE (average kinetic
energy). Rewrite any incorrect statements.
A) The water is 25 °C. — Heat or Temperature? ______________________
B) Energy flows from hot soup into the metal spoon. — Heat or Temperature?
______________________
C) Cold flows from the ice into my hand. — Heat or Temperature? ______________________
D) Particles move faster when thermal energy is added. — Heat or Temperature?
______________________
E) The thermometer shows how much energy moved. — Heat or Temperature?
______________________
F) Heat always flows from hotter to colder objects. — Heat or Temperature? ______________________
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Reflection (Criterion C/D)
In our investigation, we saw that when things got warmer, the thermometer reading went
____________________.
When things got cooler, it went ____________________.
This shows that heat moves from ____________________ to ____________________.
One place I see this in real life is ____________________.
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