Radium, Thorium, and Francium are all radioactive metallic elements. Radium is a chemical element with the symbol Ra and atomic number 88. Thorium is a naturally occurring radioactive chemical element with the symbol Th and atomic number 90. Francium is a highly radioactive metal and the second-least electronegative element, with the symbol Fr and atomic number 87. All three of these elements are found in nature and have been used in various applications.