Franci
87
Fr
Grup
1
Període
7
Bloc
s
Protons
Electrons
Neutrons
87
87
136
Propietats Generals
Nombre atòmic
87
Massa atòmica
[223]
Nombre de massa
223
Categoria
Metalls alcalins
Color
Plata
Radioactiu
Sí
Francium was named after France
Estructura cristal·lina
n/a
Història
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.
Electrons per capa
2, 8, 18, 32, 18, 8, 1
Configuració electrònica
[Rn] 7s1
Francium was the last element discovered in nature, rather than by synthesis
Propietats Físiques
Fase
Sòlid
Densitat
1,87 g/cm3
Punt de fusió
296,15 K | 23 °C | 73,4 °F
Punt d'ebullició
950,15 K | 677 °C | 1250,6 °F
Entalpia de fusió
2 kJ/mol
Entalpia de vaporització
65 kJ/mol
Capacitat tèrmica específica
-
Abundància a l'escorça terrestre
n/a
Abundància a l'univers
n/a
Número CAS
7440-73-5
Número CID de PubChem
n/a
Propietats Atòmiques
Radi atòmic
260 pm
Radi covalent
348 pm
Electronegativitat
0,7 (Escala de Pauling)
Potencial d'ionització
4,0727 eV
Volum atòmic
71,07 cm3/mol
Conductivitat tèrmica
0,15 W/cm·K
Estats d'oxidació
1
Aplicacions
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
Isòtops
Isòtops estables
-Isòtops inestables
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