Francium

87
Fr
Grupp
1
Period
7
Block
s
Protoner
Electrons
Neutroner
87
87
136
Generella Egenskaper
Atomnummer
87
Atommassa
[223]
Mass Number
223
Kategori
Alkalimetaller
Färg
Silver
Radioaktiv
Ja
Francium was named after France
Kristallstruktur
n/a
Historia
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.
Elektroner per skal
2, 8, 18, 32, 18, 8, 1
Elektronkonfiguration
[Rn] 7s1
Fr
Francium was the last element discovered in nature, rather than by synthesis
Fysikaliska Egenskaper
Aggregationstillstånd
Fast
Densitet
1,87 g/cm3
Smältpunkt
296,15 K | 23 °C | 73,4 °F
Kokpunkt
950,15 K | 677 °C | 1250,6 °F
Smältvärme
2 kJ/mol
Ångbildningsvärme
65 kJ/mol
Specifik värmekapacitet
-
Abundance in Earth's crust
n/a
Abundance in Universe
n/a
Illustration
Bildkrediter: Images-of-elements
Illustration of francium
CAS Number
7440-73-5
PubChem CID Number
n/a
Atomära Egenskaper
Atomradie
260 pm
Kovalent radie
348 pm
Elektronegativitet
0,7 (Paulingskalan)
Jonisationspotential
4,0727 eV
Molvolym
71,07 cm3/mol
Värmeledningsförmåga
0,15 W/cm·K
Oxidationstillstånd
1
Applications
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.
Francium is highly radioactive
Isotoper
Stabila isotoper
-
Instabila 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