Answer :
The chemical reaction that is exothermic (meaning it releases heat to the surroundings) is the reaction where the products have lower energy than the reactants. In simple terms, during an exothermic reaction, energy is released in the form of heat. Here's a brief explanation with an example:
1. **Example of an Exothermic Reaction**:
- **Combustion** is a common example of an exothermic reaction. When you burn a piece of paper, the reactants (paper and oxygen) combine to form products (carbon dioxide and water vapor) which have lower energy than the initial reactants. This decrease in energy leads to the release of heat and light.
2. **Characteristics of Exothermic Reactions**:
- Exothermic reactions feel warm to the touch because they release heat.
- They usually involve bonds being formed, which releases energy in the form of heat.
- In terms of energy, the reactants have higher energy compared to the products in an exothermic reaction.
3. **Energy Change in Exothermic Reactions**:
- The energy level diagram for an exothermic reaction shows that the reactants start at a higher energy level, and as the reaction progresses, they release energy and end up at a lower energy level with the products.
4. **Summary**:
- In summary, exothermic reactions are those where heat is given off to the surroundings. They typically involve a decrease in energy from reactants to products, leading to a net release of energy in the form of heat.
If you need further clarification or more examples, feel free to ask!