The decay constant is a fundamental concept in nuclear physics that quantifies the rate at which a radioactive substance disintegrates. It is denoted by the symbol λ and represents the probability per unit time that a single atom will decay. A higher decay constant indicates a faster rate of decay, while a lower value suggests a slower process. In practical terms, the decay constant is crucial for calculating the half-life of a radioactive isotope, which is the time required for half of the original amount of the substance to decay. This relationship helps scientists understand the behavior of materials like uranium or carbon-14 in various applications, including dating archaeological finds and managing nuclear waste.