Energy ChangesDeep Dive

Deep Dive: Where Does the Energy Come From?

Part of Endothermic ReactionsGCSE Chemistry

This deep dive covers Deep Dive: Where Does the Energy Come From? within Endothermic Reactions for GCSE Chemistry. Revise Endothermic Reactions in Energy Changes for GCSE Chemistry with 20 exam-style questions and 14 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 4 of 12 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 4 of 12

Practice

20 questions

Recall

14 flashcards

🔬 Deep Dive: Where Does the Energy Come From?

🌡️ Endothermic = Energy Enters

In endothermic reactions, energy is transferred FROM the surroundings INTO the reacting chemicals. This causes the temperature of the surroundings to decrease.

Energy in Products > Energy in Reactants

Energy is absorbed from surroundings to make up the difference

Common examples of endothermic reactions:

  • Photosynthesis — plants absorb light energy to make glucose
  • Thermal decomposition — breaking down compounds using heat (e.g., CaCO₃ → CaO + CO₂)
  • Dissolving ammonium nitrate — used in sports injury cold packs
  • Citric acid + sodium hydrogencarbonate — sherbet reaction
  • Electrolysis — requires continuous energy input

Keep building this topic

Read this section alongside the surrounding pages in Endothermic Reactions. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Endothermic Reactions

In an endothermic reaction, energy is:

  • A. Released to the surroundings
  • B. Absorbed from the surroundings
  • C. Created inside the reaction vessel
  • D. Neither gained nor lost
1 markfoundation

Explain why a sports cold pack becomes cold when activated.

2 marksstandard

Quick Recall Flashcards

What is an endothermic reaction?
A reaction that absorbs/takes in energy from the surroundings
What does "endo" mean?
Inside — energy enters from surroundings

Want to test your knowledge?

PrepWise has 20 exam-style questions and 14 flashcards for Endothermic Reactions — with adaptive difficulty and instant feedback.

Join Alpha