Mendeleyevium

On Scientific Themes: NEW DEVELOPMENTS IN NUCLEAR PHYSICS. (Pravda, Feb. 15, p. 4. Complete text:) Discoveries of great fundamental importance have recently been in nuclear physics. Hitherto unknown elements—einsteinium, fermium and mendeleyevium—have been obtained with the aid of atomic technology, and in 1955 and 1956 such “elementary” particles of matter as anti-protons and anti-neurons were discovered.

In 1940, Fermi created neptunium (Z = 93), the first artificial, ‘trans-uranic’, element. Others, also unstable, soon followed, among them fermium (Z = 100) and mendeleyevium (Z = 101).

THE MODERN PERIODIC TABLE HAS ALL THE MISSING GAPS FROM MENDELEYEV’S TIME FILLED IN. EACH SQUARE HAS THE ATOMIC SYMBOL IN THE CENTER, THE ATOMIC NUMBER IN THE UPPER LEFT, AND THE ATOMIC WEIGHT AT THE BOTTOM. IT ALSO INCLUDES SEVERAL ADDITIONS THAT MENDELEYEV DID NOT INCLUDE IN HIS ORIGINAL TABLE, INCLUDING THE NOBLE GASES (COLUMN 18) AND ARTIFICIALLY CREATED ELEMENTS SUCH AS ATOMIC NUMBER 101, MENDELEYEVIUM (MD).