The minimum energy a molecule should possess in order to enter into a fruitful collision is known as:

Options

A. Reaction energy
B. Collision energy
C. Activation energy
D. Threshold energy

Answer

To solve the question regarding the minimum energy a molecule should possess to enter into a fruitful collision, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Collision Theory**:
- Collision theory states that for a reaction to occur, reactant molecules must collide with each other. However, not all collisions result in a reaction.

2. **Defining Fruitful Collision**:
- A fruitful collision is defined as an effective collision where the colliding molecules have sufficient energy and proper orientation to break bonds and form new products.

3. **Minimum Energy Requirement**:
- There exists a minimum energy threshold that molecules must possess in order to undergo a reaction. This energy is crucial because it determines whether the collision will lead to a reaction or not.

4. **Terminology**:
- The minimum energy required for a molecule to participate in a fruitful collision is known as **threshold energy**.
- It is important to differentiate this from activation energy, which is the energy barrier that must be overcome for a reaction to proceed after a fruitful collision has occurred.

5. **Conclusion**:
- Therefore, the answer to the question is that the minimum energy a molecule should possess in order to enter into a fruitful collision is referred to as **threshold energy**.