Which statements describe how Becquerel, the Curies, and other scientists contributed to the cumulative understanding of radioactivity? Check all that apply. Becquerel showed that radioactivity is a form of phosphorescence. The Curies established that radioactivity is a property of an atom that does not change if changes occur to the physical or chemical properties of the atom. The Curies discovered the element uranium. Hans Geiger invented a method for detecting and measuring radioactivity. The radium girls demonstrated how to use shielding methods to protect living tissue from harmful radiation produced by radioactive elements.