The Mystery of Matter: Search for the Elements - Season 1 Episode 2 Unruly Elements (1859-1902)

Over a single weekend in 1869, a young Russian chemistry professor named Dmitri Mendeleev invents the Periodic Table, bringing order to the growing gaggle of elements. But this sense of order is shattered when a Polish graduate student named Marie Sklodowska Curie discovers radioactivity, revealing that elements can change identities — and that atoms must have undiscovered parts inside them.