Energy in Chemical Reactions
📋 What it is
Reactions release energy (exothermic, gives off heat) or absorb it (endothermic, gets cold).
🗣️ Coach says
Reactions don’t just move atoms — they move energy. Some RELEASE energy as heat or light (exothermic — burning, explosions). Others ABSORB energy and feel cold (endothermic — an instant cold pack). Whether it warms up or cools down tells you which way energy flowed.
🧠 Memory hook
Exothermic = gives OFF heat (warms up). Endothermic = takes IN heat (cools down).
😂 Giggle
What element is a girl's future best friend?
Carbon! (Because diamonds are just carbon under pressure.)
😲 Whoa!
A glow stick works by an endothermic-then-light-releasing reaction — bending it mixes chemicals that produce light with almost no heat, called “cold light”.
✅ Quick check: An instant cold pack gets cold when you squeeze it. Exothermic or endothermic?
Say your answer out loud first — then reveal.
Endothermic — it ABSORBS heat from its surroundings, which is why it feels cold.
Endothermic reactions take in energy, lowering the surrounding temperature.
🧪 Try it! (2 minutes)
Think of a campfire (releases heat, exothermic) vs a cold pack (absorbs heat, endothermic). Which way does energy flow in each?