Franciu
87
Fr
Grupă
1
Perioadă
7
Bloc
s
Protoni
Electroni
Neutroni
87
87
136
Proprietăți Generale
Număr atomic
87
Masă atomică
[223]
Numar de masa
223
Categorie
Metale alcaline
Culoare
Argint
Radioactive
Da
Francium a fost numit după Franța
Structură cristalină
n/a
Istoric
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.
Electroni pe nivelul de energie
2, 8, 18, 32, 18, 8, 1
Configurație electronică
[Rn] 7s1
Francium was the last element discovered in nature, rather than by synthesis
Proprietăți Fizice
Fază
Solid
Densitate
1,87 g/cm3
Punct de topire
296,15 K | 23 °C | 73,4 °F
Punct de fierbere
950,15 K | 677 °C | 1250,6 °F
Energie de fuziune
2 kJ/mol
Energie de evaporare
65 kJ/mol
Căldură specifică
-
Abundența în scoarța Pământului
n/a
Abundența în Univers
n/a
Numarul CAS
7440-73-5
Număr CID PubChem
n/a
Proprietăți Atomice
Rază atomică
260 pm
Rază de covalență
348 pm
Electronegativitate
0,7 (Scara lui Pauling)
Potențial de ionizare
4,0727 eV
Volum molar
71,07 cm3/mol
Conductivitate termică
0,15 W/cm·K
Număr de oxidare
1
Aplicații
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
Izotopi stabili
-Izotopi instabili
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