Fr
223.000Francium
Fransiyum
Francium is an extremely rare radioactive alkali metal with atomic number 87. It has no practical bulk uses because its isotopes are short-lived, but francium atoms are important in atomic physics and weak-interaction research.
87
223 g/mol
[Rn] 7s¹
2 | 8 | 18 | 32 | 18 | 8 | 1
0.7
1.87 g/cm³
26.85 °C
676.9 °C
Marguerite Perey
Francium was discovered in 1939 by Marguerite Perey at the Curie Institute while studying actinium decay products. It was named after France.
Francium-221
Half-life: About 4.9 minutes. Short-lived radioactive francium isotope used in research contexts.Francium-223
Half-life: About 22 minutes. Longest-lived naturally occurring francium isotope from actinium decay.- Atomic physics experiments with trapped and laser-cooled francium atoms
- Parity nonconservation and weak-interaction studies
- Spectroscopy tests of heavy alkali metal electronic structure
- Trace radiochemistry research rather than practical bulk applications
Francium has no biological role. All francium isotopes are radioactive and short-lived, and the element exists only in trace amounts.
- Francium is usually described as the second-rarest naturally occurring element after astatine, with only tens of grams estimated to exist in Earth’s crust at any moment.
- Francium should be extremely reactive as an alkali metal, but its short half-life prevents ordinary bulk chemistry.
- Marguerite Perey discovered francium while working on actinium, connecting element 87 directly to natural radioactive decay.
- Francium is studied atom by atom rather than in visible metal samples.
- Francium has atomic number 87 and symbol Fr.
- Its electron configuration is [Rn] 7s¹.
- Francium is a radioactive alkali metal.
- Remember Fr-223 for a 22-minute half-life and francium as the second-rarest naturally occurring element after astatine.
What is the atomic number of francium?
The atomic number of francium is 87.
What is the electron configuration of francium?
Francium has the electron configuration [Rn] 7s¹.
What is francium used for?
Francium has no practical bulk uses; it is used in specialized atomic physics and spectroscopy research.
Why is francium so rare?
Francium isotopes are radioactive and short-lived, so only trace amounts exist naturally at any moment.
What is francium-223?
Francium-223 is the longest-lived naturally occurring francium isotope, with a half-life of about 22 minutes.
Is francium an alkali metal?
Yes. Francium is the period 7 alkali metal in group 1.