CinnaEntry Start free
HESI ChemistryExothermic and endothermic

Energy in ReactionsHESI A2 cheat sheet

Exothermic and endothermic

9 key facts 5 practice questions Reviewed Oct 2026
The 1-minute sheetCinnaEntry

Exothermic

  • Releases energy; surroundings get warmer
  • Products have less energy than reactants
  • Combustion, neutralization, respiration

Endothermic

  • Absorbs energy; surroundings get cooler
  • Products have more energy than reactants
  • Photosynthesis, melting, instant cold packs

Activation Energy

  • The energy needed to start a reaction
  • A catalyst lowers it without being consumed

Units

  • Joules or calories; 1 cal = 4.184 J
Key takeaway

Exothermic and endothermic

Before you read

Test yourself first: 5 questions

Question 1 of 5

The energy an object has due to its motion is called:

CinnaEntry website
CinnaEntry app: the study feed with a practice question
Study Energy in Reactions in the appTEAS 7 and HESI A2 question banks with a rationale on every answer and timed practice tests.See how CinnaEntry works
Start free
Want more HESI Chemistry questions?We'll email you a free set on Energy in Reactions. No account needed.

Was this helpful?

Free to start

Know energy in reactions cold

TEAS 7 and HESI A2 question banks with a rationale on every answer and timed practice tests.

  • TEAS 7 & HESI A2 question banks
  • Rationale on every answer
  • Timed full-length practice tests
  • 300+ cheat sheets
See how CinnaEntry works
CinnaEntry website
CinnaEntry app: the study feed with a practice question