1. Exothermic - Burning gasoline releases heat energy into the surroundings.
2. Exothermic - Baking involves chemical reactions that release heat, and the oven provides heat to drive the process, but the reactions themselves are exothermic.
3. Endothermic - Melting ice requires absorbing heat from the water to break the solid structure.
4. Exothermic - The reaction between sodium and chlorine is highly energetic and releases a large amount of heat (explosive).
5. Exothermic - Burning candles releases heat, which warms the air inside the balloon, causing it to rise.
6. Exothermic - Freezing water releases heat as molecules slow down and form a solid lattice.
7. Endothermic - Boiling water requires continuous absorption of heat to change from liquid to gas.
8. Exothermic - Condensation releases heat as water vapor turns into liquid droplets.
9. Endothermic - Evaporation requires absorbing heat from the surroundings to turn liquid into gas.
10. Endothermic - Photosynthesis absorbs energy from sunlight to convert carbon dioxide and water into glucose and oxygen.
11. Endothermic - Tree growth requires energy input (from photosynthesis) to build complex molecules.
12. Endothermic - Melting snow absorbs heat from the environment to change from solid to liquid.
13. Exothermic - Mixing HCl with water releases heat, indicating an exothermic dissolution or reaction.
14. Endothermic - A cold pack absorbs heat from the injured area to reduce swelling and pain; the chemical reaction inside is endothermic.
15. Exothermic - Cooking an egg involves denaturing proteins using heat from the pan; the process releases energy as the egg solidifies.
Parent Tip: Review the logic above to help your child master the concept of endothermic and exothermic reactions worksheet.
