Francium
87
Fr
Gruppe
1
Periode
7
Blokk
s
Protoner
Elektroner
Nøytroner
87
87
136
Generelle egenskaper
Atomnummer
87
Atomvekt
[223]
Massetall
223
Kategori
Alkalimetaller
Farge
Sølv
Radioaktiv
Ja
Francium was named after France
Krystallstruktur
I/T
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 per energinivå
2, 8, 18, 32, 18, 8, 1
Elektronkonfigurasjon
[Rn] 7s1
Francium was the last element discovered in nature, rather than by synthesis
Fysikalske egenskaper
Fase
Fast stoff
Tetthet
1,87 g/cm3
Smeltepunkt
296,15 K | 23 °C | 73,4 °F
Kokepunkt
950,15 K | 677 °C | 1250,6 °F
Smeltevarme
2 kJ/mol
Fordampningsvarme
65 kJ/mol
Spesifikk varmekapasitet
-
Forekomst i jordskorpa
I/T
Forekomst i universet
I/T
CAS Number
7440-73-5
PubChem CID Number
I/T
Atomegenskaper
Atomradius
260 pm
Kovalent radius
348 pm
Elektronegativitet
0,7 (Pauling-skalaen)
Ioniseringsenergi
4,0727 eV
Molart volum
71,07 cm3/mol
Termisk ledningsevne
0,15 W/cm·K
Oksidasjonstilstander
1
Bruksområder
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