Problem #3: A sample of naturally occurring radioactive material of is decaying exponentially, with an initial amount of 630 [4 marks] units. After 6 years, the amount of radioactive material has decreased to 210 units. (a) How many units of radioactive material will there be after 12 years? (b) What is the half-life of the radioactive material (in years)? Problem #3(a): (A) 3 (B) = (C) (D)4 (E) In 2 6 1 3 (F) In 3 Problem #3(b): Select Part (b) choices. BAPS Your work has been saved!_(Back to Admin Page)