The radioactive substance strontium-90 has a half-life of 28 years. In other words, it takes 28 years for half of a given quantity of strontium-90 to decay to a non-radioactive substance. The amount of radioactive strontium-90 still present after t years is modeled by the expression 80*2^t/28 grams. Evaluate the expression for t = 0, t = 28 and t = 56. What does each value of the expression represent?

Question

anonymous · Answer

The way it is written, the function grows over time, not decays.

anonymous · Answer

How do i do the math part of it though to explain?

anonymous · Answer

80 is the initial amount of substance. t=0 is the initial time.
is the equation supposed to be 80*2^(-t/28)?