Francij
87
Fr
Skupina
1
Perioda
7
Blok
s
Protoni
Elektroni
Nevtroni
87
87
136
Splošne lastnosti
Vrstno število
87
Atomska teža
[223]
Masno število
223
Kategorija
Alkalijske kovine
Barva
Srebrna
Radioaktivno
Da
Francium was named after France
Kristalna struktura
n/p
Zgodovina
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.
Elektroni po lupinah
2, 8, 18, 32, 18, 8, 1
Razporeditev elektronov
[Rn] 7s1
Francium was the last element discovered in nature, rather than by synthesis
Fizikalne lastnosti
Faza snovi
Trdnina
Gostota
1,87 g/cm3
Tališče
296,15 K | 23 °C | 73,4 °F
Vrelišče
950,15 K | 677 °C | 1250,6 °F
Talilna toplota
2 kJ/mol
Izparilna toplota
65 kJ/mol
Toplotna kapaciteta
- J/g·K
Zastopanost v Zemljini skorji
n/p
Zastopanost v vesolju
n/p
CAS številka
7440-73-5
PubChem CID številka
n/p
Atomske lastnosti
Atomski polmer
260 pm
Kovalentni polmer
348 pm
Elektronegativnost
0,7 (Paulingova lestvica)
Ionizacijski potencial
4,0727 eV
Atomski volumen
71,07 cm3/mol
Toplotna prevodnost
0,15 W/cm·K
Oksidacijska stanja
1
Uporabe
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
Izotopi
Stabilni izotopi
-Nestabilni izotopi
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