The half-life of a chemical reaction is the time required for half of the reactant to be converted into products. It is a crucial parameter in understanding the kinetics of a reaction and indicates the reaction’s speed. In first-order reactions, the half-life remains constant, regardless of the initial concentration. The half-life (t1/2) is related to the rate constant (k) by the equation t1/2 = 0.693/k. As the reaction progresses, each successive half-life results in half of the remaining reactant being transformed. Half-life values provide insights into reaction efficiency, stability, and are essential in fields such as radioactive decay and drug kinetics.