Atoms heavier that uranium do not exist in nature.they must be synthesized in a particle accelerator.
Answer:
It was the last element first discovered in nature, rather than by synthesis. Outside the laboratory, francium is extremely rare, with trace amounts found in uranium and thorium ores, where the isotope francium-223 continually forms and decays
A radioactive element has an unstable nucleus that emits particles in the form of alpha, beta, or gamma radiation. A stable element has a nucleus that does not emit such particles
Is constant (matter that has a composition that is the same everywhere)
