Francium,  87Fr
ସାଧାରଣ ଗୁଣ
ନାମ, ପ୍ରତୀକfrancium, Fr
AppearanceUnknown, but probably metallic
ଉଚ୍ଚାରଣ/ˈfrænsiəm/
FRAN-see-əm
Francium in the periodic table
Hydrogen (other non-metal)
Helium (noble gas)
Lithium (alkali metal)
Beryllium (alkaline earth metal)
Boron (metalloid)
Carbon (other non-metal)
Nitrogen (other non-metal)
Oxygen (other non-metal)
Fluorine (halogen)
Neon (noble gas)
Sodium (alkali metal)
Magnesium (alkaline earth metal)
Aluminium (post-transition metal)
Silicon (metalloid)
Phosphorus (other non-metal)
Sulfur (other non-metal)
Chlorine (halogen)
Argon (noble gas)
Potassium (alkali metal)
Calcium (alkaline earth metal)
Scandium (transition metal)
Titanium (transition metal)
Vanadium (transition metal)
Chromium (transition metal)
Manganese (transition metal)
Iron (transition metal)
Cobalt (transition metal)
Nickel (transition metal)
Copper (transition metal)
Zinc (transition metal)
Gallium (post-transition metal)
Germanium (metalloid)
Arsenic (metalloid)
Selenium (other non-metal)
Bromine (halogen)
Krypton (noble gas)
Rubidium (alkali metal)
Strontium (alkaline earth metal)
Yttrium (transition metal)
Zirconium (transition metal)
Niobium (transition metal)
Molybdenum (transition metal)
Technetium (transition metal)
Ruthenium (transition metal)
Rhodium (transition metal)
Palladium (transition metal)
Silver (transition metal)
Cadmium (transition metal)
Indium (post-transition metal)
Tin (post-transition metal)
Antimony (metalloid)
Tellurium (metalloid)
Iodine (halogen)
Xenon (noble gas)
Caesium (alkali metal)
Barium (alkaline earth metal)
Lanthanum (lanthanoid)
Cerium (lanthanoid)
Praseodymium (lanthanoid)
Neodymium (lanthanoid)
Promethium (lanthanoid)
Samarium (lanthanoid)
Europium (lanthanoid)
Gadolinium (lanthanoid)
Terbium (lanthanoid)
Dysprosium (lanthanoid)
Holmium (lanthanoid)
Erbium (lanthanoid)
Thulium (lanthanoid)
Ytterbium (lanthanoid)
Lutetium (lanthanoid)
Hafnium (transition metal)
Tantalum (transition metal)
Tungsten (transition metal)
Rhenium (transition metal)
Osmium (transition metal)
Iridium (transition metal)
Platinum (transition metal)
Gold (transition metal)
Mercury (transition metal)
Thallium (post-transition metal)
Lead (post-transition metal)
Bismuth (post-transition metal)
Polonium (post-transition metal)
Astatine (halogen)
Radon (noble gas)
Francium (alkali metal)
Radium (alkaline earth metal)
Actinium (actinoid)
Thorium (actinoid)
Protactinium (actinoid)
Uranium (actinoid)
Neptunium (actinoid)
Plutonium (actinoid)
Americium (actinoid)
Curium (actinoid)
Berkelium (actinoid)
Californium (actinoid)
Einsteinium (actinoid)
Fermium (actinoid)
Mendelevium (actinoid)
Nobelium (actinoid)
Lawrencium (actinoid)
Rutherfordium (transition metal)
Dubnium (transition metal)
Seaborgium (transition metal)
Bohrium (transition metal)
Hassium (transition metal)
Meitnerium (unknown chemical properties)
Darmstadtium (unknown chemical properties)
Roentgenium (unknown chemical properties)
Copernicium (transition metal)
Ununtrium (unknown chemical properties)
Flerovium (unknown chemical properties)
Ununpentium (unknown chemical properties)
Livermorium (unknown chemical properties)
Ununseptium (unknown chemical properties)
Ununoctium (unknown chemical properties)
Cs

Fr

Uue
radonfranciumradium
ପରମାଣୁ କ୍ରମାଙ୍କ (Z)87
ଶ୍ରେଣୀ, ବ୍ଳକgroup 1 (alkali metals), s-block
ପର୍ଯ୍ୟାୟperiod 7
ମୌଳିକ ପ୍ରକାର  alkali metal
ମାନକ ପରମାଣବିକ ଓଜନ (Ar)(223)
ଇଲେକ୍‌ଟ୍ରୋନ୍ ବିନ୍ୟାସ[Rn] 7s1
per shell
2, 8, 18, 32, 18, 8, 1
ଭୌତିକ ଗୁଣ
ଅବସ୍ଥାsolid presumably
ଗଳନାଙ୍କ? 300 K ​(? 27 °C, ​? 80 °F)
ସ୍ଫୁଟନାଙ୍କ? 950 K ​(? 677 °C, ​? 1250 °F)
Density near r.t.? 1.87 (extrapolated) g/cm3
Heat of fusionca. 2 kJ/mol
Heat of ca. 65 kJ/mol
 pressure (extrapolated)
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 404 454 519 608 738 946
Atomic properties
Oxidation states1 (strongly basic oxide)
ElectronegativityPauling scale: 0.7
Covalent radius260 (extrapolated) pm
Van der Waals radius348 (extrapolated) pm
Miscellanea
Crystal structure ​cubic body-centered (extrapolated)
Thermal conductivity15 (extrapolated) W/(m·K)
Electrical resistivity3 µ (calculated) Ω·m
Magnetic orderingParamagnetic
CAS Number7440-73-5
ଇତିହାସ
ଆବିଷ୍କାରMarguerite Perey (1939)
First isolationMarguerite Perey (1939)
Most stable isotopes of francium
iso NA half-life DM DE (MeV) DP
221Fr trace 4.8 min α 6.457 217At
222Fr syn 14.2 min β 2.033 222Ra
223Fr trace 22.00 min β 1.149 223Ra
α 5.430 219At
| references

References