According to the collision theory which one of the following statements is correct?

The colliding molecules should have proper orientation and at least threshold energy for the reaction to occur.

The correct answer is Option (1) → The colliding molecules should have proper orientation and at least threshold energy for the reaction to occur.

According to collision theory:

• For a reaction to occur, molecules must collide with:
1. Proper orientation
2. Sufficient energy (equal to or greater than the activation energy)

Other statements are incorrect:

• Energy less than threshold → reaction does not occur

•  Proper orientation alone is not enough. Sufficient energy is also required.

• Not all collisions are effective. Rate depends on effective collisions, not total collisions.