Question

a scientist has 400 grams of a radioactive substance with a half - life of one year. the amount of the substance that the scientist has after t years is represented by the expression (400(0.5)^{t}). which kind of expression is (400(0.5)^{t})?
options: quadratic, linear, exponential growth, exponential decay

Explanation:

The expression follows the exponential form $A(t) = A_0(b)^t$, where $A_0=400$ is the initial amount, and the base $b=0.5$ is between 0 and 1. When the base of an exponential function is in this range, it describes a quantity that decreases over time, which is exponential decay. Radioactive decay is a classic example of this type of behavior.

Answer:

exponential decay