To tell the difference between endothermic and exothermic reactions, you need to know a few important things:

1. What They Mean:

   • Endothermic reactions take in heat. This makes them feel cold.
   • Exothermic reactions give off heat. This makes them feel warm.

2. Energy Changes:

   • Look at the energy levels of the starting materials (reactants) and the final products:
     • If the products have more energy, it is an endothermic reaction.
     • If the products have less energy, it is an exothermic reaction.

3. Temperature Changes:

   • Pay attention to any changes in temperature during the reaction.
     • If the temperature goes up, you have an exothermic reaction.
     • If the temperature goes down, you have an endothermic reaction.

By noticing these signs, you can get better at spotting what type of reaction you’re dealing with just by observing the materials involved!