Overview

Grade 8 Science

Chemical Reactions

9. Types

9.2 Energy Changes, Endothermic and exothermic

Endothermic vs. Exothermic Reactions: Where Does the Energy Go?

Discover how chemical reactions either absorb or release energy, and learn to identify each type using real-world examples, energy diagrams, and key vocabulary.

What You'll Learn

Exothermic reactions release heat, warming the surrounding environment noticeably.

Endothermic reactions absorb heat, causing surrounding temperatures to decrease significantly.

Activation energy is required to start both endothermic and exothermic chemical reactions.

Energy diagrams and enthalpy changes reveal whether reactions absorb or release energy.

What You'll Practice

Students identify endothermic and exothermic reactions using observable temperature changes.

Learners analyze energy diagrams and classify reactions using enthalpy change values.

Practice connects real-world examples like cold packs and photosynthesis to concepts.

Why This Matters

Understanding endothermic and exothermic reactions equips students to explain everyday phenomena from cold packs and hand warmers to photosynthesis and combustion and builds essential foundations for advanced chemistry and physical science.

This Unit Includes

Practice exercises

Learning resources

Skills

Endothermic

Exothermic

Activation Energy

Enthalpy

Calorimetry

NL Curriculum Aligned