An exothermic reaction is one in which the reacting substances :

Options

A. Have same energy as products
B. Have less energy than the products
C. Have more energy than the products
D. Are at higher temperature than the products

Answer

To answer the question, "An exothermic reaction is one in which the reacting substances:", we need to analyze the characteristics of exothermic reactions.

### Step-by-Step Solution:

1. **Definition of Exothermic Reaction**:
An exothermic reaction is a type of chemical reaction that releases energy in the form of heat to its surroundings. This means that during the reaction, the energy of the products is lower than the energy of the reactants.

2. **Energy Comparison**:
In an exothermic reaction, the reactants have more energy than the products. This is because the excess energy is released during the reaction, typically as heat.

3. **Enthalpy Change**:
The change in enthalpy (ΔH) for an exothermic reaction is negative. This indicates that energy is released. Therefore, we can conclude that the enthalpy of the products is less than that of the reactants.

4. **Conclusion**:
Based on the above points, we can summarize that in an exothermic reaction, the reacting substances (reactants) have more energy than the products.

### Final Answer:
An exothermic reaction is one in which the reacting substances have more energy than the products.

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