According to collision theory, which of the following conditions must be met for a chemical reaction to occur when molecules or atoms collide?

• A. The colliding particles must have identical masses.
• B. The colliding particles must be in the gaseous state.
• C. The colliding particles must have sufficient energy and the correct orientation.
• D. The colliding particles must be electrically neutral.

Answer: (C)

Verified step by step guidance

1. Understand that collision theory explains how chemical reactions occur based on the collisions between reactant particles (atoms, ions, or molecules).
2. Recognize that for a reaction to happen, colliding particles must have enough kinetic energy to overcome the activation energy barrier; this is called having 'sufficient energy.'
3. Know that the orientation of the colliding particles matters because molecules must align in a way that allows bonds to break and new bonds to form; this is the 'correct orientation' requirement.
4. Note that the masses of the colliding particles do not need to be identical; particles of different masses can react as long as energy and orientation conditions are met.
5. Also, the particles do not necessarily have to be in the gaseous state or electrically neutral; collision theory applies broadly, but the key conditions are sufficient energy and correct orientation.