Francium

Atomic number

87

Atomic mass (u)

223.01973

Category

Alkali metal

Standard state

Solid

Melting point

26.85 °C (300 K)

Boiling point

Not reported

Density (g/cm³)

Not reported in this source

Electronegativity (Pauling)

0.7

Electron configuration

[Rn]7s1

Oxidation states

+1

Atomic radius (pm)

348

First ionization energy (eV)

3.9

Discovery & recognition

Discovery year / period (PubChem)

1939

Discovery credited to (RSC)

Marguerite Perey

Date or period recorded by RSC

1939

Discovery place

Curie Institute, Paris, France

An ancient date does not identify a first human discovery. Different references may date observation, isolation and formal recognition differently.

Natural occurrence & production

The creation of an element’s nuclei and its concentration into terrestrial deposits are different processes. The occurrence note below concerns its presence or production on Earth; it is not a complete account of nucleosynthesis.

“Francium is obtained by the neutron bombardment of radium in a nuclear reactor.”

Royal Society of Chemistry · occurrence excerpt ↗

Continue the research

Reference values are not product specifications. Blank values have not been estimated. For superheavy elements, some properties and family assignments are theoretical or incompletely measured.