The half-lives of cobalt-60 and strontium-90 are 5.3 years and 28 years respectively. Suppose that samples of cobalt-60 and strontium-90 are such that they initially have the same activity. What will be true of the numbers of cobalt-60 and strontium-90 nuclei in these samples?
It is not possible to compare numbers of nuclei without knowing the masses of the samples.
There will be more cobalt-60 than strontium-90 nuclei.
There will be more strontium-90 than cobalt-60 nuclei.
There will be equal numbers of cobalt-60 and strontium-90 nuclei.