(Radioactive Decay: Conceptual) A class of students is analysing two hypothetical…
CHEMISTRY · Multi-part · US High School · Chemistry · Atomic Structure & Nuclear · Atomic Structure & Nuclear
Problem
(Radioactive Decay: Conceptual)
A class of students is analysing two hypothetical radioactive isotopes, P and Q. Isotope P has a half-life that is three times longer than that of isotope Q.
Answer the following questions based on this information.
(i) Define the term “half-life” of a radioactive substance.
(ii) Explain qualitatively how the numerical value of the decay constant is related to the speed at which a radioactive sample decays.
(iii) Without carrying out any numerical calculation, state which isotope, P or Q, will display a steeper fall in activity when equal initial activities of the two isotopes are plotted on the same graph of activity versus time. Give a brief justification based on your explanation in part (ii).