On a graph of the number of undecayed nuclei versus time for a radioactive isotope

CHEMISTRY · Single correct · US High School · Chemistry · Atomic Structure & Nuclear · Atomic Structure & Nuclear

Problem

On a graph of the number of undecayed nuclei

N

versus time

t

for a radioactive isotope, which time interval defines the isotope’s half-life? (a) The time between successive peak values of

N

on the graph (b) The time required for

N

to decrease to

\dfrac{1}{e}

of its initial value (c) The time required for

N

to decrease to one-half of its initial value (d) The time required for

N

to decrease to one-fourth of its initial value