2. Step 1: Energy must be SUPPLIED to break chemical bonds: Step 2: Energy is RELEASED when new chemical bonds are made:

3.  A change (like a chemical reaction) that requires (or absorbs) heat  So what would it feel like?

4.  Endothermic reactions take in heat and the temperature drops reaction

6.  A change (like a chemical reaction) that releases heat.

7.  Exothermic reactions give off heat and the temperature of the substance rises  So what would it feel like? reaction

8. Exothermic Combustion of fuels Yeast & Hydrogen Peroxide Epsom salts & water Endothermic Photosynthesis Acetic Acid (vinegar) & Sodium Bicarbonate (baking soda)