Question

a sciientist places 3500 grams of a radioactive substance on a try for a expeeriment the substances loses 25% of its mass each hour due to radioactive decay write a exponetnial model

Answer 1

Let t be time in hours. Since 25% is lost each hour, 75% (0.75) remains each hour. The exponential decay model is

M(t) = 3500(0.75)^t grams, for t ≥ 0.

Equivalently, using base e,
M(t) = 3500 e^{-kt} with k = −ln(0.75) ≈ 0.28768, so M(t) = 3500 e^{-0.28768 t}.