In chemical kinetics, only a small fraction of colliisons lead to reactions. This is because

Options

A. The colliding molecuels may not be appropriately oriented to one another and the colliisons are not energetic.
B. The colliding molecuels are properly oriented to one another and the colliison are highly energetic.
C. The colliding molecules are properly oriented to one another and the colliisons are not highly enrgetic.
D. The colliding molecules may not be appropriately oriented to one another and the colliison are very enrgetic.

Explanation

**Step-by-Step Solution:**

1. **Understanding Collision Theory**:
- In chemical kinetics, the 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. **Effective Collisions**:
- For a collision to be effective (i.e., lead to a reaction), two conditions must be met:
- The colliding molecules must be properly oriented relative to each other.
- The colliding molecules must possess sufficient energy to overcome the activation energy barrier.

3. **Orientation of Molecules**:
- Proper orientation means that the molecules must align in a way that allows the necessary bonds to break and form. If the molecules collide in an incorrect orientation, the reaction will not occur, even if they have enough energy.

4. **Energy of Collisions**:
- The energy of the colliding molecules must be greater than or equal to the activation energy required for the reaction. If the energy is too low, the molecules will not react, regardless of their orientation.

5. **Conclusion**:
- Therefore, only a small fraction of collisions lead to reactions because many collisions do not meet the criteria of proper orientation and sufficient energy. This results in a low probability of successful reactions occurring.

**Final Statement**:
In summary, the reason why only a small fraction of collisions leads to reactions is that colliding molecules may not be properly oriented, and the collisions may not have sufficient energy to result in a reaction.

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