All these elements are natural radioactive elements.
Some radioactive elements in the periodic table are radium, uranium, plutonium, thorium, polonium, radon, francium, astatine, radium, and curium.
Francium is a naturally occurring radioactive element that is produced as a decay product of uranium and thorium. It is found in tiny amounts in uranium and thorium ores. Francium was first discovered in 1939 by Marguerite Perey in France.
Natural polonium exist in uranium and thorium ores.
Francium exists in uranium and thorium ores.
Francium exist in uranium and thorium ores but it is not exploitable.
Polonium exist in traces in uranium and thorium ores.
Francium exist in infinitesimal traces in thorium and uranium ores.
Natural francium exist in uranium and thorium ores.Artificial francium is obtained in particle accelerators.
Polonium isotopes are decay products of thorium or uranium.
Natural francium exist in uranium and thorium ores.
Francium exist in uranium and thorium ores; the chemical form is not known.
francium is found in thorium and uranium ores in the earth's crust obtained by the decay of actinium