Exothermic vs. Endothermic Reactions
Exothermic and endothermic reactions are two types of chemical reactions that are distinguished by the heat energy they either release or absorb.

Exothermic Reaction:
- In an exothermic reaction, energy is released in the form of heat.
- This type of reaction typically feels warm to the touch.
- The reactants have higher energy than the products, resulting in the excess energy being released into the surroundings.
- Examples of exothermic reactions include combustion, neutralization reactions, and some types of oxidation reactions.

Endothermic Reaction:
- In an endothermic reaction, energy is absorbed from the surroundings in the form of heat.
- This type of reaction typically feels cool to the touch.
- The products have higher energy than the reactants, requiring energy input to form them.
- Examples of endothermic reactions include photosynthesis, thermal decomposition, and the reaction between citric acid and baking soda.

Differences:
1. Energy Exchange: Exothermic reactions release energy, while endothermic reactions absorb energy.
2. Temperature Change: Exothermic reactions usually increase the temperature of the surroundings, whereas endothermic reactions decrease the temperature.
3. Reactants and Products: In exothermic reactions, the products have lower energy than the reactants; in endothermic reactions, the products have higher energy than the reactants.
In summary, exothermic reactions release heat energy, while endothermic reactions absorb heat energy. Understanding the differences between these two types of reactions is crucial in various fields, including chemistry, biology, and physics.