Science Matter & Materials Conceptual 12–13 yrs

Reactions That Release or Absorb Heat

放热与吸热反应

Description

Distinguish between exothermic reactions (release energy, temperature rises) and endothermic reactions (absorb energy, temperature falls), with everyday and industrial examples

Mastery Evidence

✓ Defines exothermic and endothermic in terms of energy transfer to and from the surroundings
✓ Gives two examples of each type from everyday life (e.g. combustion, hand warmers; photosynthesis, cold packs)
✓ Explains energy changes during changes of state (melting is endothermic, freezing is exothermic)
✓ Interprets a temperature change in an experiment to classify the reaction type

Assessment Prompt

If your child shook a sports cold pack to activate it and it got cold, or lit a match and it got hot, could they explain what type of reaction is happening in each case and why one gets hot while the other gets cold?