Cesi

Cesi (Cs)

chemical element with symbol Cs and atomic number 55
Atomic Number55
Atomic Weight132.90545196
Rhif màs133
Group1
Period6
Blocks
Proton55 p+
Niwtron78 n0
Electron55 e-
Animated Bohr model of Cs (Cesi)

Nodwedd Ffisegol

Atomic Radius
260 pm
molar volume
covalent radius
232 pm
Metallic Radius
235 pm
ionic radius
167 pm
Crystal Radius
181 pm
Van der Waals radius
343 pm
density
1.873 g/cm³
Atomic Radii Of The Elements: Cesi0102030405060708090100110120130140150160170180190200210220230240250260270280290300310320330340350pmAtomic RadiusCovalent RadiusMetallic RadiusVan der Waals radius

Nodwedd Gemegol

egni
proton affinity
electron affinity
0.471626 eV/particle
ionization energy
3.893905548 eV/particle
ionization energy of Cs (Cesi)
enthalpy of vaporization
68.3 kJ/mol
enthalpy of fusion
2.09 kJ/mol
standard enthalpy of formation
76.5 kJ/mol
Electron
plisgyn yr electron2, 8, 18, 18, 8, 1
Bohr model: Cs (Cesi)
valence electron1
Lewis structure: Cs (Cesi)
trefn yr electronnau[Xe] 6s1
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s1
Enhanced Bohr model of Cs (Cesi)
Orbital Diagram of Cs (Cesi)
Cyflwr ocsidiad-1, 1
Electronegatifedd
0.79
Electrophilicity Index
0.696095447101947 eV/particle
cyflwr sylfaenol mater
cyflwr materSolid
gaseous state of matter
Boiling Point
944.15 K
Melting Point
301.65 K
critical pressure
9.4 MPa
critical temperature
1,938.15 K
triple point
appearance
lliw
Silver
appearancesilvery gold
Mynegrif plygiant
nodwedd ffisegol gwrthrych
Thermal Conductivity
35.9 W/(m K)
thermal expansion
molar heat capacity
32.21 J/(mol K)
Specific Heat Capacity
0.242 J/(g⋅K)
heat capacity ratio
electrical properties
typeConductor
dargludedd trydanol
5 MS/m
Gwrthedd
0.0000002 m Ω
superconductivity
magnetism
typeparamagnetic
magnetic susceptibility (Mass)
0.0000000028 m³/Kg
magnetic susceptibility (Molar)
0.000000000372 m³/mol
magnetic susceptibility (Volume)
0.00000526
magnetic ordering
Curie temperature
Néel temperature
strwythur
Crystal StructureBody Centered Cubic (BCC)
lattice constant
6.05 Å
Lattice Anglesπ/2, π/2, π/2
nodwedd mecanyddol deunyddiau
hardness
0.2 MPa
bulk modulus
1.6 GPa
shear modulus
Young's modulus
1.7 GPa
Poisson's ratio
speed of sound
classification
CategoryAlkali metals, Alkali metals
CAS GroupIA
IUPAC GroupIA
Glawe Number8
Mendeleev Number5
Pettifor Number8
Geochemical Classalkali metal
Goldschmidt classificationlitophile

other

Gas Basicity
polarizability
400.9 ± 0.7 a₀
C6 Dispersion Coefficient
allotrope
Neutron cross section
29
Neutron Mass Absorption
0.0077
quantum number2S1/2
space group229 (Im_3m)

Isotopes of Cesium

Stable Isotopes1
Unstable Isotopes41
Natural Isotopes1

111Cs

Rhif màs111
neutron number56
relative atomic mass
110.953945 ± 0.000215 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
spin3/2
nuclear quadrupole moment
dyddiad darganfod
parity+

decay modeintensity
p (proton emission)

112Cs

Rhif màs112
neutron number57
relative atomic mass
111.950172 ± 0.000124 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
490 ± 30 us
spin1
nuclear quadrupole moment
dyddiad darganfod1994
parity+

decay modeintensity
p (proton emission)100%
α (α emission)0.26%

113Cs

Rhif màs113
neutron number58
relative atomic mass
112.944428484 ± 0.000009207 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
16.94 ± 0.09 us
spin3/2
nuclear quadrupole moment
dyddiad darganfod1984
parity+

decay modeintensity
p (proton emission)100%

114Cs

Rhif màs114
neutron number59
relative atomic mass
113.941292244 ± 0.000091323 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
570 ± 20 ms
spin1
nuclear quadrupole moment
dyddiad darganfod1978
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%
α (α emission)0.018%
β+ p (β+-delayed proton emission)8.7%
β+α (β+-delayed α emission)0.19%

115Cs

Rhif màs115
neutron number60
relative atomic mass
114.93591 ± 0.00011 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
1.4 ± 0.8 s
spin9/2
nuclear quadrupole moment
dyddiad darganfod1978
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)0.07%

116Cs

Rhif màs116
neutron number61
relative atomic mass
115.933395 ± 0.000108 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
700 ± 40 ms
spin1
nuclear quadrupole moment
dyddiad darganfod1975
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)0.28%
β+α (β+-delayed α emission)0.049%

117Cs

Rhif màs117
neutron number62
relative atomic mass
116.928616723 ± 0.000067 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
8.4 ± 0.6 s
spin9/2
nuclear quadrupole moment
dyddiad darganfod1972
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%

118Cs

Rhif màs118
neutron number63
relative atomic mass
117.926559517 ± 0.00001369 Da
g-factor
1.935 ± 0.0025
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
14 ± 2 s
spin2
nuclear quadrupole moment
1.31 ± 0.17
dyddiad darganfod1969
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)0.021%
β+α (β+-delayed α emission)0.0012%

119Cs

Rhif màs119
neutron number64
relative atomic mass
118.922377327 ± 0.000014965 Da
g-factor
1.2111111111111 ± 0.0066666666666667
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
43 ± 0.2 s
spin9/2
nuclear quadrupole moment
2.65 ± 0.17
dyddiad darganfod1969
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+α (β+-delayed α emission)2%

120Cs

Rhif màs120
neutron number65
relative atomic mass
119.920677277 ± 0.000010702 Da
g-factor
1.93 ± 0.01
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
60.4 ± 0.6 s
spin2
nuclear quadrupole moment
1.36 ± 0.07
dyddiad darganfod1969
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+α (β+-delayed α emission)2%
β+ p (β+-delayed proton emission)7%

121Cs

Rhif màs121
neutron number66
relative atomic mass
120.917227235 ± 0.00001534 Da
g-factor
0.51266666666667 ± 0.0026666666666667
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
155 ± 4 s
spin3/2
nuclear quadrupole moment
0.79 ± 0.04
dyddiad darganfod1969
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%

122Cs

Rhif màs122
neutron number67
relative atomic mass
121.916108144 ± 0.000036164 Da
g-factor
0.133 ± 0.002
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
21.18 ± 0.19 s
spin1
nuclear quadrupole moment
-0.179 ± 0.01
dyddiad darganfod1969
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+α (β+-delayed α emission)2%

123Cs

Rhif màs123
neutron number68
relative atomic mass
122.91299606 ± 0.000013 Da
g-factor
2.75 ± 0.014
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
5.88 ± 0.03 m
spin1/2
nuclear quadrupole moment
0
dyddiad darganfod1954
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%

124Cs

Rhif màs124
neutron number69
relative atomic mass
123.912247366 ± 0.000009823 Da
g-factor
0.672 ± 0.003
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
30.9 ± 0.4 s
spin1
nuclear quadrupole moment
-0.69 ± 0.04
dyddiad darganfod1969
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%

125Cs

Rhif màs125
neutron number70
relative atomic mass
124.909725953 ± 0.000008304 Da
g-factor
2.814 ± 0.014
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
44.35 ± 0.29 m
spin1/2
nuclear quadrupole moment
0
dyddiad darganfod1954
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%

126Cs

Rhif màs126
neutron number71
relative atomic mass
125.909445821 ± 0.00001112 Da
g-factor
0.776 ± 0.004
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
1.64 ± 0.02 m
spin1
nuclear quadrupole moment
-0.64 ± 0.03
dyddiad darganfod1954
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%

127Cs

Rhif màs127
neutron number72
relative atomic mass
126.907417527 ± 0.000005987 Da
g-factor
2.914 ± 0.014
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
6.25 ± 0.1 h
spin1/2
nuclear quadrupole moment
0
dyddiad darganfod1950
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%

128Cs

Rhif màs128
neutron number73
relative atomic mass
127.907748452 ± 0.000005771 Da
g-factor
0.972 ± 0.005
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
3.64 ± 0.014 m
spin1
nuclear quadrupole moment
-0.54 ± 0.03
dyddiad darganfod1951
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%

129Cs

Rhif màs129
neutron number74
relative atomic mass
128.90606591 ± 0.000004888 Da
g-factor
2.978 ± 0.016
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
32.06 ± 0.06 h
spin1/2
nuclear quadrupole moment
0
dyddiad darganfod1950
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%

130Cs

Rhif màs130
neutron number75
relative atomic mass
129.906709281 ± 0.000008971 Da
g-factor
1.458 ± 0.007
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
29.21 ± 0.04 m
spin1
nuclear quadrupole moment
-0.056 ± 0.006
dyddiad darganfod1952
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)98.4%
β (β decay)1.6%

131Cs

Rhif màs131
neutron number76
relative atomic mass
130.905468457 ± 0.00000019 Da
g-factor
1.4144 ± 0.0012
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
9.689 ± 0.016 d
spin5/2
nuclear quadrupole moment
0.59 ± 0.02
dyddiad darganfod1947
parity+

decay modeintensity
ϵ (electron capture)100%

132Cs

Rhif màs132
neutron number77
relative atomic mass
131.90643774 ± 0.000001112 Da
g-factor
1.1095 ± 0.0035
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
6.48 ± 0.006 d
spin2
nuclear quadrupole moment
0.48 ± 0.02
dyddiad darganfod1953
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)98.13%
β (β decay)1.87%

133Cs

Rhif màs133
neutron number78
relative atomic mass
132.905451958 ± 0.000000008 Da
g-factor
0.73651428571429 ± 0.0004
natural abundance
100
Dadfeilio ymbelydrolstable isotope
Hanner oesNot Radioactive ☢️
spin7/2
nuclear quadrupole moment
-0.00343 ± 0.0001
dyddiad darganfod1921
parity+

134Cs

Rhif màs134
neutron number79
relative atomic mass
133.906718501 ± 0.000000017 Da
g-factor
0.747325 ± 0.00035
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
2.065 ± 0.0004 y
spin4
nuclear quadrupole moment
0.37 ± 0.02
dyddiad darganfod1940
parity+

decay modeintensity
β (β decay)100%
ϵ (electron capture)0.0003%

135Cs

Rhif màs135
neutron number80
relative atomic mass
134.905976907 ± 0.00000039 Da
g-factor
0.77951428571429 ± 0.00037142857142857
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
1.33 ± 0.19 My
spin7/2
nuclear quadrupole moment
0.048 ± 0.003
dyddiad darganfod1949
parity+

decay modeintensity
β (β decay)100%

136Cs

Rhif màs136
neutron number81
relative atomic mass
135.907311431 ± 0.00000201 Da
g-factor
0.741 ± 0.003
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
13.01 ± 0.05 d
spin5
nuclear quadrupole moment
0.213 ± 0.015
dyddiad darganfod1951
parity+

decay modeintensity
β (β decay)100%

137Cs

Rhif màs137
neutron number82
relative atomic mass
136.907089296 ± 0.000000324 Da
g-factor
0.81068571428571 ± 0.0004
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
30.04 ± 0.04 y
spin7/2
nuclear quadrupole moment
0.048 ± 0.002
dyddiad darganfod1951
parity+

decay modeintensity
β (β decay)100%

138Cs

Rhif màs138
neutron number83
relative atomic mass
137.911017119 ± 0.000009831 Da
g-factor
0.233 ± 0.0013333333333333
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
33.5 ± 0.2 m
spin3
nuclear quadrupole moment
0.112 ± 0.017
dyddiad darganfod1943
parity-

decay modeintensity
β (β decay)100%

139Cs

Rhif màs139
neutron number84
relative atomic mass
138.913363822 ± 0.000003364 Da
g-factor
0.768 ± 0.0011428571428571
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
9.27 ± 0.05 m
spin7/2
nuclear quadrupole moment
-0.063 ± 0.014
dyddiad darganfod1939
parity+

decay modeintensity
β (β decay)100%

140Cs

Rhif màs140
neutron number85
relative atomic mass
139.917283707 ± 0.000008801 Da
g-factor
0.134 ± 0.001
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
63.7 ± 0.3 s
spin1
nuclear quadrupole moment
-0.094 ± 0.015
dyddiad darganfod1950
parity-

decay modeintensity
β (β decay)100%

141Cs

Rhif màs141
neutron number86
relative atomic mass
140.920045279 ± 0.000009871 Da
g-factor
0.69457142857143 ± 0.0028571428571429
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
24.84 ± 0.16 s
spin7/2
nuclear quadrupole moment
-0.42 ± 0.07
dyddiad darganfod1962
parity+

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)0.0342%

142Cs

Rhif màs142
neutron number87
relative atomic mass
141.924299514 ± 0.000007586 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
1.687 ± 0.01 s
spin0
nuclear quadrupole moment
0
dyddiad darganfod1962
parity-

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)0.089%

143Cs

Rhif màs143
neutron number88
relative atomic mass
142.927347346 ± 0.00000813 Da
g-factor
0.57933333333333 ± 0.0026666666666667
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
1.802 ± 0.008 s
spin3/2
nuclear quadrupole moment
0.44 ± 0.03
dyddiad darganfod1962
parity+

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)1.62%

144Cs

Rhif màs144
neutron number89
relative atomic mass
143.932075402 ± 0.000021612 Da
g-factor
-0.545 ± 0.003
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
994 ± 6 ms
spin1
nuclear quadrupole moment
0.29 ± 0.02
dyddiad darganfod1967
parity-

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)2.98%

145Cs

Rhif màs145
neutron number90
relative atomic mass
144.935528927 ± 0.000009733 Da
g-factor
0.522 ± 0.0026666666666667
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
582 ± 4 ms
spin3/2
nuclear quadrupole moment
0.58 ± 0.06
dyddiad darganfod1971
parity+

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)12.8%

146Cs

Rhif màs146
neutron number91
relative atomic mass
145.940621867 ± 0.000003106 Da
g-factor
-0.514 ± 0.002
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
321.6 ± 0.9 ms
spin1
nuclear quadrupole moment
0.21 ± 0.03
dyddiad darganfod1971
parity-

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)14.2%
2n (2-neutron emission)

147Cs

Rhif màs147
neutron number92
relative atomic mass
146.944261512 ± 0.000009 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
230.5 ± 0.9 ms
spin3/2
nuclear quadrupole moment
dyddiad darganfod1978
parity+

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)28.5%

148Cs

Rhif màs148
neutron number93
relative atomic mass
147.949639026 ± 0.000014 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
151.8 ± 1 ms
spin2
nuclear quadrupole moment
dyddiad darganfod1978
parity-

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)28.7%
2n (2-neutron emission)

149Cs

Rhif màs149
neutron number94
relative atomic mass
148.953516 ± 0.000429 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
112.3 ± 2.5 ms
spin3/2
nuclear quadrupole moment
dyddiad darganfod1979
parity+

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)25%
2n (2-neutron emission)

150Cs

Rhif màs150
neutron number95
relative atomic mass
149.959023 ± 0.000429 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
81 ± 2.6 ms
spin2
nuclear quadrupole moment
dyddiad darganfod1979
parity-

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)44%
2n (2-neutron emission)

151Cs

Rhif màs151
neutron number96
relative atomic mass
150.963199 ± 0.000537 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
59 ± 19 ms
spin3/2
nuclear quadrupole moment
dyddiad darganfod1979
parity+

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)
2n (2-neutron emission)

152Cs

Rhif màs152
neutron number97
relative atomic mass
151.968728 ± 0.000537 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
spin
nuclear quadrupole moment
dyddiad darganfod1987
parity

decay modeintensity
β (β decay)
β n (β-delayed neutron emission)
Cesium

hanes

darganfyddwr neu ddyfeisiwrGustov Kirchoff, Robert Bunsen
man darganfodGermany
dyddiad darganfod1860
geirdarddiadLatin: coesius (sky blue); for the blue lines of its spectrum.
ynganiadSEE-zi-em (Saesneg)

source

Abundance
Abundance in Earth's crust
natural abundance (cefnfor)
0.0003 mg/L
natural abundance (corff dynol)
0.000002 %
natural abundance (Awyrfaen)
0.000014 %
natural abundance (Haul)
0.0000008 %
Abundance in Universe
0.00000008 %

Nuclear Screening Constants

1s1.0957
2p4.1804
2s14.4884
3d14.0194
3p18.4222
3s18.6226
4d32.1616
4p29.1424
4s27.9576
5p41.349
5s39.5555
6s48.637