Question

The half-life of a radioactive element is five years. A scientist has 18 grams of the element. The equation

Answer 1

Answer:

The equation that describes the amount of mass left after a time t of a radioactive isotope is the following:

where

is the mass of the sample at t = 0

is the half-life of the sample

For the element X in this problem,

We want to find the time t at which

So we need to re-arrange the equation making t the subject:

Step-by-step explanation: