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Properties of substance:
francium
Group of substances:
inorganic
Empirical formula (Hill's system for organic substances):
Fr
Structural formula as text:
Fr
Molar/atomic mass: 223
Melting point (°C):
20
Boiling point (°C):
650
Numerical data:
Year of discovery: 1939
Density:
2.4 (20°C, g/cm
3
)
Half-life:
202
87
Fr = 0.34 s (α)
203
87
Fr = 0.7 s (α)
204
87
Fr = 2.1 s (α)
205
87
Fr = 3.7 s (α)
206
87
Fr = 16 s (α (85%), electron capture (15%))
207
87
Fr = 14.8 s (α (93%) electron capture (7%))
208
87
Fr = 59 s (α (74%), electron capture (26%))
209
87
Fr = 50 s (α (89%), electron capture (11%))
210
87
Fr = 3.18 min (α. electron capture)
211
87
Fr = 3.10 min (α. electron capture)
212
87
Fr = 20.0 min (α (44%), electron capture (56%))
213
87
Fr = 34.6 s (α (99.45%), electron capture (0.55%))
214
87
Fr = 0.005 s (α)
214m
87
Fr = 0.00335 s (α)
215
87
Fr = 90 ns (α)
216
87
Fr = 700 ns (α)
217
87
Fr = 22 μs (α)
218
87
Fr = 700 μs (α)
219
87
Fr = 0.021 s (α)
220
87
Fr = 27.4 s (α (99.65%), β (0.35%))
221
87
Fr = 4.9 min (α. heavy cluster emission
14
C (0.000 000 000 44%))
222
87
Fr = 14.4 min (β (> 99%), α (0.01-0.1%))
223
87
Fr = 21.8 min (β (> 99%), α (about 0.005%))
224
87
Fr = 2..67 min (β)
225
87
Fr = 3.9 min (β)
226
87
Fr = 48 s (β)
227
87
Fr = 2.4 min (β)
228
87
Fr = 39 s (β)
229
87
Fr = 50 s (β)
230
87
Fr = 19.1 s (β
-
(100%))
231
87
Fr = 17.6 s (β
-
(100%))
232
87
Fr = 5 s (β
-
(100%))
Electrode potential:
Fr
+
+ e
-
→ Fr, E = -2.9 V (water, 25°C)
Molar heat capacity at constant pressure C
p
(298.15 K, J/(mol·K)):
31.6 (s)
ΔH
sublimation
(kJ/mol):
69.1
References:
Бекман И.Н. Радиохимия. Том II: Радиоактивные элементы. - М.: Издатель Мархитин П.Ю., 2014. - pp. 90-94 [Russian]
Гринвуд Н., Эрншо А. Химия элементов. - Т.1. - М.: БИНОМ. Лаборатория знаний, 2008. - pp. 75 [Russian]
Лаврухина А.К., Поздняков А.А. Аналитическая химия технеция, прометия, астатина и франция. - М.: Наука, 1966. - pp. 260-301 [Russian]
Свойства элементов. - под общей редакцией Дрица М.Е. - М.: Металлургия, 1985. - pp. 60-61 [Russian]
Физические величины. - Под ред. Григорьева И.С., Мейлихова Е.З. - М.: Энергоатомиздат, 1991. - pp. 1036-1037, 1090 [Russian]
Химическая энциклопедия. - Т. 5. - М.: Советская энциклопедия, 1999. - pp. 187 [Russian]
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© Collected Ruslan Anatolievich Kiper, burewestnik@mail.ru