Case: Read the passage and answer the following questions

A property of a reaction called molecularity helps in understanding its mechanism. The number of reacting species (atoms, ions, or molecules) taking part in an elementary reaction, which must collide simultaneously in order to bring about a chemical reaction is called molecularity of a reaction.

2HI → H₂ + I₂. What kind of a reaction is this?

Bimolecular

Bimolecular reactions involve simultaneous collision between two species.