Around 1923-1924 Louis de Broglie created the wave -particle theory.The wave particle theory suggests that electrons are a type of matyter and that they travel in waves.de Broglie first got inspired from Einstein's E=mc^2 formula.It wasn't until later though, that his theory was able to be proven correct.
Soddy worked with Rutherford to explain that radioactivity is caused by an element's transmutation.They showed that when radioactive elements decay into other elements,alpha,beta and gamma radiation is produced.Soddy showed that radioactive elements may have more than one atomic mass, even if the chemical properties were identical.This became known as "isotopes".Thomson later showed that non-radioactive elements have multiple isotopes
Discovered the element, Radium with her husband. The element really helped out the medical industry for cancer treatment. Later, Curie's daughter discovered artificial radiation and Marie's granddaughter continues Nuclear research like the rest of her family. Marie Curie died of Leukemia from the extensive exposure to the radiation of her studies.
In 1897, Joseph John (JJ) Thomsojn discovered the electrons with experiments that involved electric currents passing through gas at a low temperature.This experiment is known as the cathode ray tube.Thomson is also known for his "plum pudding" model.Thomson thought that the atom was a sphere filled with fluid that had a positive charge.Throughout the fliuids,the electrons were scattered.Ernest Rutherford later disproved this model by proving the existence of the nucleus.
Was 1st to define atom in terms of weight & provide chemical evidence of its existence. Atomic theory was that each element is made of indivisible atoms, Atoms of any element are all alike but differ from atoms of other elements. He thought of an atom as a solid ball of mass.