Answer: normal energy of the reactant molecules.
- A average kinetic energy of the products
- B normal energy of the reactant molecules
- C enthalpy change of the reaction
- D activation energy of the reverse step
Correct answer: B. normal energy of the reactant molecules
Explanation: Threshold energy = activation energy + the average energy already possessed by the normal reactant molecules; only molecules reaching this energy can react.
First-order decay curve: concentration halves every t½, and that half-life is constant - a defining test for first-order kinetics.
Concept context
Study the speed of reactions and what affects it: concentration, temperature, and catalysts. Covers rate law, order of reaction, the Arrhenius equation, and reaction mechanisms step by step.