Exponential decay refers to a process where a quantity decreases at a rate proportional to its current value. This means that as time passes, the amount diminishes rapidly at first and then slows down over time. A common example of exponential decay is the way radioactive materials, like uranium, lose their radioactivity over time. In mathematical terms, exponential decay can be represented by the equation N(t) = N_0 e^-kt , where N(t) is the quantity at time t , N_0 is the initial quantity, k is the decay constant, and e is the base of natural logarithms. This concept is important in various fields, including physics, biology, and finance, where it helps model processes like population decline or the depreciation of assets.