Complete the table for the radioactive isotope. (Round your answers to two decimal places.)

Isotope 226Ra

Half-Life = 1599

Initial amount = 250 g

Find the decay after 1000 years

Fine the amount after 2,000 years

The amount of substance at any time t is given by the equation,

At = A1 x e^-kt

From the given half-life,

At/A1 = 0.5 = e^-k (1599)

The value of k is 4.3349x10^-4

Using the same equation for the next items

(1000 years) At = (250 g) x e^ (-4.3349x10^-4) (1000) = 162.06 grams

(2000 years) At = (250 g) x e^ (-4.3349x10^-4) (2000) = 105.05 grams