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 ...

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 ...

With atomic number 88, it has four natural isotopes of atomic ... dense nucleus in the atom - radium proved the key to unlocking the atom's structure. Radium's main practical use has been in medicine, ...