Unit Plan 21 (Grade 8 Science): Thermal Energy Transfer

Focus: Plan and conduct investigations to explore how mass, type of matter, and energy transfer affect temperature change and average kinetic energy of particles.

Grade Level: 8

Subject Area: Science (Physical Science • Energy • Matter & Interactions)

Total Unit Duration: 5 sessions (one week), 50–60 minutes per session

I. Introduction

Students investigate how thermal energy moves between objects and how that affects temperature change. Building on prior work with kinetic energy and particle motion, they explore how mass and type of matter (e.g., water vs. metal vs. sand) influence how quickly and how much temperature changes when the same amount of energy is transferred. Students plan and carry out simple investigations, collect and interpret data, and build models that link energy transfer, mass, material, and average kinetic energy of particles. By the end of the week, they can explain why some materials “heat up” or “cool down” faster than others and how scientists use investigations to uncover these relationships.

Essential Questions

• What is thermal energy, and how is it related to temperature and the average kinetic energy of particles?
• How does mass affect how much the temperature changes when a material gains or loses the same amount of energy?
• How does the type of matter (material) influence temperature change during energy transfer?
• How can we design and carry out an investigation that shows relationships among energy transfer, mass, material, and temperature change?
• Why does understanding thermal energy transfer matter for everyday choices (cooking, clothing, climate, building materials)?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Distinguish between thermal energy (total energy of particle motion) and temperature (a measure related to average kinetic energy of particles).
2. Describe qualitatively how adding or removing thermal energy changes the average kinetic energy of particles and thus temperature.
3. Plan and carry out a controlled investigation to examine how mass of a sample affects its temperature change when it receives the same energy input.
4. Plan and carry out a controlled investigation to examine how type of matter (e.g., water vs. metal vs. sand) affects temperature change under similar energy transfer conditions.
5. Analyze and interpret data (tables, graphs) from their investigations to identify relationships among energy transfer, mass, type of matter, and temperature change.
6. Use particle and energy-transfer models to explain why different materials and masses show different temperature changes for the same energy input.

Standards Alignment — 8th Grade (NGSS-based custom)

• MS-PS3-4 — Plan and conduct an investigation to determine the relationships among energy transfer, type of matter, mass, and change in average kinetic energy of the particles (observed as temperature change).
  • In this unit, students plan and perform investigations that vary mass and type of matter, collect temperature data, and interpret results with particle-motion models.

Success Criteria — Student Language

• I can explain the difference between thermal energy and temperature, and how both connect to particle motion.
• I can help plan an investigation that tests how mass or type of matter affects temperature change when energy is transferred.
• I can collect and graph temperature data and look for patterns relating mass, material, and temperature change.
• I can explain, using data and models, why some materials heat up or cool down more for the same amount of energy.
• I can use the language of energy transfer, mass, type of matter, and average kinetic energy when describing my results.