Because of this, Jean Baptiste Perrin, Nobel Prize winner and Hulubei's mentor, endorsed moldavium as the true eka-caesium over Marguerite Perey's recently discovered francium.
42.
Francium was discovered by Marguerite Perey in France ( from which the element takes its name ) in 1939 . It was the last element discovered in nature, rather than by synthesis.
43.
As a result of its extreme rarity in nature, most francium is synthesised in the nuclear reaction 197 n, yielding francium-209, francium-210, and francium-211.
44.
As a result of its extreme rarity in nature, most francium is synthesised in the nuclear reaction 197 n, yielding francium-209, francium-210, and francium-211.
45.
As a result of its extreme rarity in nature, most francium is synthesised in the nuclear reaction 197 n, yielding francium-209, francium-210, and francium-211.
46.
As a result of its extreme rarity in nature, most francium is synthesised in the nuclear reaction 197 n, yielding francium-209, francium-210, and francium-211.
47.
Francium was discovered by Marguerite Perey in France ( from which the element takes its name ) in 1939 . It was the last element first discovered in nature, rather than by synthesis.
48.
The least stable ground state isotope is francium-215, with a half-life of 0.12 ?s . ( 9.54 MeV alpha decay to astatine-211 ):
49.
Technically, a photo captures the emission of light, so one would think that these photos are fine, but in reality, all you're seeing is energy, not francium.
50.
Radioisotopes of francium would presumably be dangerous as well due to their high decay energy and short half-life, but none have been produced in large enough amounts to pose any serious risk.
