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 weight 228 ... This behaviour was used to deduce the existence of a compact, dense nucleus in the atom - radium proved the key to ...