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Properties of substance:
caesium
Synonyms:
cesium
Group of substances:
inorganic
Physical appearance:
yellowish cubic metal
Empirical formula (Hill's system for organic substances):
Cs
Structural formula as text:
Cs
Molar/atomic mass: 132.91
Melting point (°C):
28.5
Boiling point (°C):
672
Solubility (g/100 g of solvent):
ammonia liquid
: 333.5 (-50°C) [
Ref.
]
cesium chloride fused
: 7.8 (646°C) [
Ref.
]
ethanol
: reaction [
Ref.
]
ethylenediamine
: 0.797 (20°C) [
Ref.
]
hexamethylphosphoric triamide
: very soluble [
Ref.
]
lithium molten
: soluble [
Ref.
]
mercury
: 4.54 (18°C) [
Ref.
]
methylamine
: soluble [
Ref.
]
water
: reaction [
Ref.
]
Numerical data:
Year of discovery: 1860
Ionization Potentials (Electronvolts): 3.89397
Ionization Potentials (Electronvolts): 25.1
Hardness on the Mohs’ scale: 0.2
Density:
1.9039 (20°C, g/cm
3
)
1.836 (28.5°C, g/cm
3
)
1.887 (28.5°C, g/cm
3
)
1.78 (127°C, g/cm
3
)
1.552 (527°C, g/cm
3
)
Reactions:
[
Ref.1
]
2Cs/Hg + 2H
2
O → 2CsOH + H
2
+ 2Hg
[
Ref.1
,
Ref.2
]
4Cs + O
2
→ 2Cs
2
O
Half-life:
112
55
Cs = 490 μs (p (about 100%))
113
55
Cs = 17.7 μs (p (100%))
114
55
Cs = 570 ms (β
+
(about 100%), β
+
p (8.7%), α (0.018%), β
+
α (0.19%))
115
55
Cs = 1.4 s (β
+
(100%), β
+
p (0.07%))
116
55
Cs = 700 ms (β
+
(100%), β
+
p (0.28%), β
+
α (0.049%))
117
55
Cs = 8.4 s (β
+
(100%))
117m
55
Cs = 6.5 s (β
+
(100%))
118
55
Cs = 14 s (β
+
(100%), β
+
p (0.021%), β
+
α (0.0012%))
119
55
Cs = 43.0 s (β
+
(100%))
119m
55
Cs = 30.4 s (β
+
(100%))
120
55
Cs = 60.4 s (β
+
(100%))
121
55
Cs = 155 s (β
+
(100%))
121m
55
Cs = 122 s (β
+
(83%), internal transition (17%))
122
55
Cs = 21.18 s (β
+
(100%))
122n
55
Cs = 3.70 min (β
+
(100%))
123
55
Cs = 5.88 min (β
+
(100%))
123m
55
Cs = 1.64 s (internal transition (100%))
123n
55
Cs = 114 ns (internal transition (100%))
124
55
Cs = 30.9 s (β
+
(100%))
124m
55
Cs = 6.3 s (internal transition (100%))
125
55
Cs = 46.7 min (β
+
(100%))
125m
55
Cs = 900 μs (internal transition (100%))
126
55
Cs = 1.64 min (β
+
(100%))
126n
55
Cs = 171 μs (internal transition (100%))
127
55
Cs = 6.25 h (β
+
(100%))
127m
55
Cs = 55 μs (internal transition (100%))
128
55
Cs = 3.640 min (β
+
(100%))
129
55
Cs = 32.06 h (β
+
(100%))
129m
55
Cs = 718 ns (internal transition (100%))
130
55
Cs = 29.21 min (β
+
(98.4%), β
-
(1.6%))
131
55
Cs = 9.689 d (electron capture (100%))
132
55
Cs = 6.480 d (β
+
(98.13%), β
-
(1.87%))
133
55
Cs = stable ( (isotopic abundance 100%))
134
55
Cs = 2.0648 y (β
-
(100%))
134m
55
Cs = 2.903 h (internal transition (100%))
135
55
Cs = 2 300 000 y (β
-
(100%))
135m
55
Cs = 53 min (internal transition (100%))
136
55
Cs = 13.16 d (β
-
(100%))
136m
55
Cs = 17.5 s (internal transition (?))
137
55
Cs = 30.1671 y (β
-
(100%))
138
55
Cs = 33.41 min (β
-
(100%))
139
55
Cs = 9.27 min (β
-
(100%))
140
55
Cs = 63.7 s (β
-
(100%))
141
55
Cs = 24.84 s (β
-
(100%), β
-
n (0.035%))
142
55
Cs = 1.684 s (β
-
(100%), β
-
n (0.090%))
143
55
Cs = 1.791 s (β
-
(100%), β
-
n (1.64%))
144
55
Cs = 994 ms (β
-
(100%), β
-
n (3.03%))
145
55
Cs = 582 ms (β
-
(100%), β
-
n (14.7%))
146
55
Cs = 323 ms (β
-
(100%), β
-
n (14.2%))
147
55
Cs = 230 ms (β
-
(100%), β
-
n (28.5%))
Vapour pressure (Torr):
1 (278°C)
10 (387°C)
100 (515°C)
200 (570°C)
400 (635°C)
Electrode potential:
Cs
+
+ e
-
→ Cs, E = -2.923 V (water, 25°C)
Viscosity (mPa·s):
0.63 (43.4°C)
0.475 (99.6°C)
0.375 (168°C)
Standard molar enthalpy (heat) of formation Δ
f
H
0
(298.15 K, kJ/mol):
0 (s)
Standard molar Gibbs energy of formation Δ
f
G
0
(298.15 K, kJ/mol):
0 (s)
Standard molar entropy S
0
(298.15 K, J/(mol·K)):
84.35 (s)
Molar heat capacity at constant pressure C
p
(298.15 K, J/(mol·K)):
32 (s)
Molar enthalpy (heat) of fusion Δ
fus
H (kJ/mol):
2.09
Enthalpy (heat) of vaporization Δ
vap
H (kJ/mol):
68.28
Critical temperature (°C):
1427
References:
Journal of the American Chemical Society. - 1939. - Vol. 61, No. 3. - pp. 709-715 [DOI:
10.1021/ja01872a049
]
Гринвуд Н., Эрншо А. Химия элементов. - Т.1. - М.: БИНОМ. Лаборатория знаний, 2008. - pp. 83 [Russian]
Гурвич Я.А. Справочник молодого аппаратчика-химика. - М.: Химия, 1991. - pp. 52 [Russian]
Локшин Э.П., Воскобойников Н.Б. Рубидий и цезий. - Апатиты, 1996 [Russian]
Методы элементоорганической химии: Литий, натрий, калий, рубидий, цезий. - Кн.2. - М.: Наука, 1971. - pp. 1141-1143 [Russian]
Некрасов Б.В. Основы общей химии. - Т.2. - М.: Химия, 1973. - pp. 220-226 [Russian]
Неорганические синтезы. - Сб. 1. - М.: ИИЛ, 1951. - pp. 10 [Russian]
Плющев В.Е., Степин Б.Д. Аналитическая химия рубидия и цезия. - М.: Наука, 1975. - pp. 12-13 [Russian]
Плющев В.Е., Степин Б.Д. Химия и технология соединений лития, рубидия и цезия. - М.: Химия, 1970. - pp. 72-80 [Russian]
Рабинович В.А., Хавин З.Я. Краткий химический справочник. - Л.: Химия, 1977. - pp. 111 [Russian]
Редкие и рассеянные элементы. Химия и технология. - Кн. 1. - М.: Мисис, 1996. - pp. 68-70 [Russian]
Свойства элементов. - под общей редакцией Дрица М.Е. - М.: Металлургия, 1985. - pp. 54-60 [Russian]
Филянд М.А., Семенова Е.И. Свойства редких элементов. - 2-е изд. - М.: Металлургия, 1964. - pp. 232-240 [Russian]
Химическая энциклопедия. - Т. 5. - М.: Советская энциклопедия, 1999. - pp. 331-333 [Russian]
Энциклопедия для детей. - Т.17: Химия. - М.: Аванта+, 2004. - pp. 184 [Russian]
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© Collected Ruslan Anatolievich Kiper, burewestnik@mail.ru