Three radioisotopes are being discussed in a chemistry class. Technetium-99m has a half-life of 6 hours. Rubidium-87 has a half-

life of 50 billion years. Which describes who would most likely use each isotope? A geologist would use technetium-99m because short-life indicates an older organism, and a doctor would use rubidium-87 because it allows for a more-accurate measurement of disease.
A doctor would use technetium-99m because a short half-life indicates a quick measurement, and a geologist would use rubidium-87 because a longer half-life means that there is a longer time to measure old rock.
A doctor would use technetium-99m because a short half-life indicates a quick measurement, and an archeologist would use rubidium-87 because anything containing carbon also contains rubidium.
A geologist would use technetium-99m because a short half-life indicates an older organism, and an archeologist would use rubidium-87 because anything containing carbon also contains rubidium.