Rubidium-87 is the radioactive isotope which takes the greatest amount of time to undergo the change.
What is an Isotope?
These are referred to as atoms with the same number of protons but different numbers of neutrons.
The radioactive isotope which will take the greatest amount of time to undergo the change is Rubidium-87 because it contains the most amount of years according to the graph.
Read more about Radioactive isotope here https://brainly.com/question/2285425
#SPJ2
