-0.121 The nuclei of radioactive (unstable) chemical elements decay (disintegrate) in a way that can be
modelled by exponential functions.
A radioactive element decays according to the equation N= Ae' where N is the number of
radioactive nuclei present r hours after the experiment begins, and A is a constant
a) If 350 radioactive nuclei are present in the element at the beginning of the experiment find the
number of radioactive nuclei, N. present after 10 hours.
b) Draw a graph of N against r.
c) Find how long it would take before 50 radioactive nuclei are left
d) Would there ever be no radioactive nuclei left? Give reasons for your answer