Question 19 (Mandatory) (1 point) A radioactive sample with an initial mass of 35 mg has a half-life of 3 days. Which of the following equations models the exponential decay for time, t, in days? a) A=35(2)^(1)/(3) b) A=35((1)/(2))^(1)/(3) c) A=35(2)^(3)/(2) d) A=35((1)/(2))^(3)/(2)

## Step 1: Calculate the fraction of the sample remaining after t days.### The half-life is 3 days, meaning the sample halves every 3 days. After days, the number of half-lives that have passed is . Therefore, the fraction of the sample remaining is .## Step 2: Determine the equation for the remaining mass.### The initial mass is 35 mg. Multiply the initial mass by the fraction remaining to find the mass after days: .