The decay constant, which is a parameter used to describe the exponential decay of a radioactive substance, is typically denoted by the symbol λ (lambda). The SI unit for the decay constant is reciprocal seconds, represented as s⁻¹ or more commonly, 1/s.
The decay constant represents the probability of a radioactive atom decaying per unit time and has the dimension of time⁻¹. It is often used in equations related to radioactive decay, such as the exponential decay equation:
N(t) = N₀ * e^(-λt),
where N(t) is the number of radioactive atoms remaining at time t, N₀ is the initial number of radioactive atoms, e is the base of the natural logarithm (approximately 2.71828), λ is the decay constant, and t is the time.
So, when calculating or expressing the decay constant, it is important to use the appropriate unit of reciprocal seconds (s⁻¹ or 1/s) to ensure dimensional consistency in equations and calculations.