Lesson Plan

• Describe the concept of thermal equilibrium and the zero‑law of thermodynamics.
• Explain why equal temperature implies no net heat flow between regions.
• Predict temperature changes when two objects at different temperatures are placed in thermal contact.
• Apply the condition T₁ = T₂ to determine whether systems are in equilibrium.
• Identify and correct common misconceptions about temperature and heat flow.

• Projector or interactive whiteboard
• Printed diagram of metal block on wooden board
• Thermometers or temperature probes
• Metal block and wooden board for demonstration
• Worksheet with “Check Your Understanding” questions
• Markers and whiteboard
• Calculator (optional)

Begin with a quick question: “What happens to heat when two objects at different temperatures touch?” Students recall prior lessons on heat flow. Explain that today they will determine how equal temperatures indicate thermal equilibrium and what that means for energy transfer.

1. Do‑now (5'): Mini‑quiz on heat flow concepts displayed on the board.
2. Mini‑lecture (10'): Introduce thermal equilibrium, zero‑law, and the equation T₁ = T₂ using a diagram.
3. Guided demonstration (10'): Place a metal block on a wooden board, monitor temperatures, and discuss the observed equalisation.
4. Collaborative worksheet (15'): Groups answer “Check Your Understanding” questions while the teacher circulates.
5. Concept‑mapping activity (5'): Students create a quick map linking temperature, heat flow, equilibrium, and the zero‑law.
6. Whole‑class recap & formative check (5'): Quick poll or show‑of‑hands to confirm mastery of objectives.

Summarise that equal temperatures mean no net heat flow and that the zero‑law lets us treat temperature as a property of a system. Ask students to write one‑sentence exit tickets describing thermal equilibrium in their own words. Assign homework: complete the textbook problems on the zero‑law and temperature gradients.