Photo: Niels Bohr's research notes for his new atomic theory Rutherford's find ... emitted by the radioactive element radium) at a sheet of gold foil only 1/3000 of an inch thick, and tracing ...

radium, Ernest Rutherford, alpha rays, beta rays, gamma rays, radioactive decay, half-life, atomic structure Email us at [email protected] if you have questions about the footage and are ...