Threshold energy =energy of normal molecules + Activation energy.

Answer

To determine whether the statement "Threshold energy = energy of normal molecules + Activation energy" is true or false, we can analyze the concepts of threshold energy, activation energy, and the energy of normal molecules.

### Step-by-Step Solution:

1. **Define Threshold Energy**:
- Threshold energy is the minimum energy that reactants must possess in order to undergo a chemical reaction. It is the energy required to reach the transition state.

2. **Define Activation Energy**:
- Activation energy (Ea) is the additional energy required to convert the reactants into the activated complex (transition state). It is the energy barrier that must be overcome for the reaction to proceed.

3. **Energy of Normal Molecules**:
- The energy of normal molecules refers to the average kinetic energy of the molecules at a given temperature. This energy is typically less than the activation energy.

4. **Relationship Between the Energies**:
- In a reaction, the total energy of the molecules (energy of normal molecules) plus the activation energy must equal the threshold energy. This can be expressed mathematically as:
\[ \text{Threshold Energy} = \text{Energy of Normal Molecules} + \text{Activation Energy} \]

5. **Conclusion**:
- Since the equation holds true based on the definitions and relationships of the energies involved in a chemical reaction, we conclude that the statement is **true**.

### Final Answer:
The statement "Threshold energy = energy of normal molecules + Activation energy" is **True**.