Francium
87
Fr
Gruppe
1
Periode
7
Blok
s
Protoner
Elektroner
Neutroner
87
87
136
Generelle Egenskaber
Atomnummer
87
Atommasse
[223]
Masseantal
223
Kategori
Alkalimetaller
Farve
Sølv
Radioaktiv
Ja
Francium was named after France
Krystalstruktur
n/a
Historie
Francium was discovered in 1939 by Marguerite Perey of the Curie Institute in Paris, France.
It was discovered when she was researching the radioactive decay of actinium-227.
Marguerite Perey discovered that francium-223 is made naturally when actinium-227 emits an alpha-particle.
It was discovered when she was researching the radioactive decay of actinium-227.
Marguerite Perey discovered that francium-223 is made naturally when actinium-227 emits an alpha-particle.
Elektroner i hver skal
2, 8, 18, 32, 18, 8, 1
Elektronkonfiguration
[Rn] 7s1
Francium was the last element discovered in nature, rather than by synthesis
Fysiske Egenskaber
Tilstandsform
Fast stof
Massefylde
1,87 g/cm3
Smeltepunkt
296,15 K | 23 °C | 73,4 °F
Kogepunkt
950,15 K | 677 °C | 1250,6 °F
Smeltevarme
2 kJ/mol
Fordampningsvarme
65 kJ/mol
Varmefylde
-
Forekomst i jordskorpen
n/a
Forekomst i universet
n/a
CAS-nummer
7440-73-5
PubChem CID-nummer
n/a
Atomare egenskaber
Atomradius
260 pm
Kovalent radius
348 pm
Elektronegativitet
0,7 (Paulings skala)
Ioniseringspotentiale
4,0727 eV
Atomvolumen
71,07 cm3/mol
Varmeledningsevne
0,15 W/cm·K
Oxidationstrin
1
Anvendelser
Due to its instability and rarity, there are no commercial applications for francium.
It has been used for research purposes in the fields of biology and of atomic structure.
Its use as a potential diagnostic aid for various cancers has also been explored, but this application has been deemed impractical.
It has been used for research purposes in the fields of biology and of atomic structure.
Its use as a potential diagnostic aid for various cancers has also been explored, but this application has been deemed impractical.
Francium is highly radioactive
Isotoper
Stabile isotoper
-Ustabile isotoper
199Fr, 200Fr, 201Fr, 202Fr, 203Fr, 204Fr, 205Fr, 206Fr, 207Fr, 208Fr, 209Fr, 210Fr, 211Fr, 212Fr, 213Fr, 214Fr, 215Fr, 216Fr, 217Fr, 218Fr, 219Fr, 220Fr, 221Fr, 222Fr, 223Fr, 224Fr, 225Fr, 226Fr, 227Fr, 228Fr, 229Fr, 230Fr, 231Fr, 232Fr