Lesson Plan

• Describe the concept of absolute zero and its significance on the thermodynamic temperature scale.
• Explain why 0 K is the lowest possible temperature and how particle motion behaves at this limit.
• Convert temperatures between Kelvin, Celsius, and Fahrenheit using the appropriate equations.
• Identify real‑world phenomena that provide experimental evidence for absolute zero.

• Projector and screen
• Temperature‑conversion worksheet
• Handout with temperature‑scale diagram
• Graph paper and calculators
• Clicker/quiz app for concept checks

Begin with a striking image of a cryogenic laboratory to spark curiosity about extreme cold. Ask students what they already know about Celsius and Fahrenheit scales, linking that knowledge to the idea of an absolute temperature limit. Explain that by the end of the lesson they will be able to define absolute zero, convert between scales, and cite evidence for its existence.

1. Do‑now (5') – Quick temperature‑conversion worksheet to activate prior knowledge.
2. Mini‑lecture (10') – Introduce absolute zero, kinetic energy, and zero‑point energy; show the Kelvin scale definition.
3. Demonstration (8') – Display a graph of specific heat approaching zero and discuss experimental evidence (ideal‑gas extrapolation, superconductivity).
4. Guided practice (12') – Students work in pairs to fill a conversion table and annotate the diagram of freezing/boiling points across scales.
5. Check for understanding (5') – Concept‑question poll via clicker and an exit‑ticket prompt.

Recap that absolute zero (0 K) marks the lowest thermodynamic temperature and that all three scales intersect at this point. Collect exit‑ticket responses to gauge mastery and assign a short homework: research one low‑temperature phenomenon (e.g., Bose‑Einstein condensation) and write a paragraph linking it to absolute zero.