Glenn Seaborg reordered the Periodic Table- put the actinide series below the lanthanide series. (9 h 26 m, 1 ene 1940 año – 0 h 3 m, 31 dic 1940 año)
Descripción:
Actinide- Atomic numbers from 89-103. 15 elements, named after Actinium, first element in series. Used in nuclear reactors and bombs.Lanthanide- Atomic numbers from 57-71. 15 metals, rare earth elements. Silvery-white metals, similar to Lanthanum, first element in group. Found naturally on Earth.
"Inner Transition Elements". Rare elements listed at bottom of Periodic Table.
Añadido al timeline:
fecha:
9 h 26 m, 1 ene 1940 año
0 h 3 m, 31 dic 1940 año
~ 12 months