Energy | Substitute Teacher
Students review the concept of energy in chemistry, including forms of energy, energy transfer, and endothermic versus exothermic changes. This lesson is designed for a substitute teacher and uses simple examples, guided discussion, and a short exit assessment.
| Term | Definition |
|---|---|
| Energy | The ability to do work or cause change. |
| Endothermic | A process that absorbs energy from the surroundings. |
| Exothermic | A process that releases energy to the surroundings. |
| Reaction profile diagram | A graph that shows energy changes during a reaction. |
| System | The part of the universe being studied, such as the chemicals involved in a reaction. |
| Surroundings | Everything outside the system. |
Write two questions on the board: 'What is energy?' and 'Where do we see energy changes in daily life?' Briefly discuss student responses and connect them to chemistry.
Respond orally or in writing with examples such as batteries, food, burning, or melting.
Explain the definition of energy and review endothermic and exothermic processes using simple examples. Emphasize that energy can be transferred but is not created or destroyed.
Take notes and answer quick questions during the explanation.
Draw a simple energy profile diagram on the board. Model how to identify reactants, products, activation energy, and whether the process is endothermic or exothermic.
Label a copy in notebooks and answer teacher prompts.
Give students 3-4 short scenarios, such as ice melting, hand warmers, or burning a candle. Ask them to classify each as endothermic or exothermic and explain their reasoning in one sentence.
Complete the classifications and write brief explanations.
Review answers as a class, then distribute a short exit ticket with 3 questions: define energy, identify endothermic/exothermic, and interpret one simple diagram or scenario.
Complete the exit ticket individually and hand it in before leaving.
End with a 1-minute recap: energy is the ability to cause change, and in chemistry energy is either absorbed or released during a process. Remind students to look for clues in examples and diagrams when deciding whether a change is endothermic or exothermic.
Formative assessment includes class responses, guided practice, partner/independent practice, and a 3-question exit ticket to check understanding of energy, endothermic/exothermic changes, and basic diagram interpretation.