Rubidium (Rb)

chemical element with symbol Rb and atomic number 37

Atomic Number	37
Atomic Weight	85.4678
mass number	85

Group	1
Period	5
Block	s

proton	37 p⁺
neutron	48 n⁰
electron	37 e^-

Physical Property

Atomic Radius	235 pm 240 pm
molar volume	55.9 cm³/mol
Covalent Radius	210 pm 202 pm 225 pm 220 pm
Metallic Radius	216 pm 248 pm
ionic radius	152 pm 156 pm 161 pm 163 pm 166 pm 169 pm 172 pm 183 pm
Crystal Radius	166 pm 170 pm 175 pm 177 pm 180 pm 183 pm 186 pm 197 pm
Van der Waals radius	290 pm 303 pm 325 pm 303 pm 411.4 pm
density	1.53 g/cm³ 1460 kg/m³

Chemical Property

{ERROR}

energia

proton affinity
electron affinity	0.48592 eV/particle
ionization energy	4.177128 eV/particle 27.28954 eV/particle 39.247 eV/particle 52.2 eV/particle 68.4 eV/particle 82.9 eV/particle 98.67 eV/particle 132.8 eV/particle 150.63 eV/particle 277.12 eV/particle 313.1 eV/particle 356 eV/particle 400 eV/particle 443 eV/particle 502 eV/particle 550 eV/particle 601 eV/particle 654 eV/particle 706 eV/particle 857 eV/particle 905.3 eV/particle 958.9 eV/particle 1024 eV/particle 1080 eV/particle 1125 eV/particle 1242.5 eV/particle 1294.567 eV/particle 3133.3 eV/particle 3281 eV/particle 3442 eV/particle 3600 eV/particle 3815 eV/particle 3988 eV/particle 4214 eV/particle 4356.865 eV/particle 18305.883 eV/particle 18965.51 eV/particle

enthalpy of vaporization	75.8 kJ/mol
enthalpy of fusion	2.2 kJ/mol
standard enthalpy of formation	80.9 kJ/mol
electron

Tegimen electronicum	2, 8, 18, 8, 1

valence electron	1 ⓘ

electron configuration	[Kr] 5s¹ⓘ 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹

oxidation number	-1, 1
electronegativity	4.177 eV/particle 0.104686 0.82
Electrophilicity Index	0.7363448717297969 eV/particle
fundamental state of matter

phase of matter
gaseous state of matter
Boiling Point	961.15 K
Melting Point	312.45 K
critical pressure	16 MPa
critical temperature	2093.15 K
Punctum triplex	312.41 K
appearance
Color	Black #ff1493 #702eb0 #702eb0
appearance	grey white
refractive index
thermodynamic material property
Thermal Conductivity	58.2 W/(m K)
thermal expansion
molar heat capacity	31.06 J/(mol K)
Specific Heat Capacity	0.363 J/(g⋅K)
heat capacity ratio
electrical properties
type	Conductor
electrical conductivity	8.3 MS/m
electrical resistivity	0.00000012 Ω*m
Superconductrum
magnetism
type	paramagnetic
magnetic susceptibility (Mass)	0.0000000026 m³/Kg
magnetic susceptibility (Molar)	0.000000000222 m³/mol
magnetic susceptibility (Volume)	0.00000398
magnetic ordering
Curie temperature
Néel temperature
structure
Crystal Structure	{ERROR}
lattice constant	5.59 Å
Lattice Angles	π/2, π/2, π/2
mechanical property
hardness	0.216 MPa 0.3 MPa
bulk modulus	2.5 GPa
shear modulus
Young's modulus	2.4 GPa
Poisson's ratio
celeritas soni	1300 m/s
classificare
Category	Actinides, Alkali metals
CAS Group	IA
IUPAC Group	IA
Glawe Number	9
Mendeleev Number	4
Pettifor Number	9
Geochemical Class	alkali metal
Goldschmidt classification	litophile

other

Gas Basicity
polarizability	319.8 ± 0.3 a₀
C6 Dispersion Coefficient	4769 a₀ 4660 a₀
allotrope
Neutron cross section	0.38
Neutron Mass Absorption	0.0003
quantum number	2S1/2
space group	229 (Im_3m)

Isotopes of Rubidium

Stable Isotopes	1
Unstable Isotopes	33
Natural Isotopes	2

⁷¹Rb

mass number	71
neutron number	34
Relative Atomic Mass	70.965335 ± 0.000429 Da
g-factor
natural abundance
radioactivitas	☢️ radioactive element
half-life
Volubilitas	5/2
nuclear quadrupole moment
repertus
parity	-

decay mode	intensity
p (proton emission)

⁷²Rb

mass number	72
neutron number	35
Relative Atomic Mass	71.958851 ± 0.000537 Da
g-factor
natural abundance
radioactivitas	☢️ radioactive element
half-life	103 ± 22 ns
Volubilitas	1
nuclear quadrupole moment
repertus	2017
parity	+

decay mode	intensity
p (proton emission)

⁷³Rb

mass number	73
neutron number	36
Relative Atomic Mass	72.950604506 ± 0.000043794 Da
g-factor
natural abundance
radioactivitas	☢️ radioactive element
half-life
Volubilitas	3/2
nuclear quadrupole moment
repertus	1996
parity	-

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)
p (proton emission)	100%

⁷⁴Rb

mass number	74
neutron number	37
Relative Atomic Mass	73.944265867 ± 0.000003249 Da
g-factor	0
natural abundance
radioactivitas	☢️ radioactive element
half-life	64.78 ± 0.03 ms
Volubilitas	0
nuclear quadrupole moment	0
repertus	1977
parity	+

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

⁷⁵Rb

mass number	75
neutron number	38
Relative Atomic Mass	74.9385732 ± 0.000001266 Da
g-factor	0.386 ± 0.00066666666666667
natural abundance
radioactivitas	☢️ radioactive element
half-life	19 ± 1.2 s
Volubilitas	3/2
nuclear quadrupole moment	0.81 ± 0.04
repertus	1975
parity	-

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

⁷⁶Rb

mass number	76
neutron number	39
Relative Atomic Mass	75.935073031 ± 0.000001006 Da
g-factor	-0.372552 ± 0.000011
natural abundance
radioactivitas	☢️ radioactive element
half-life	36.5 ± 0.6 s
Volubilitas	1
nuclear quadrupole moment	0.41 ± 0.09
repertus	1969
parity	-

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺α (β⁺-delayed α emission)	3.8%

⁷⁷Rb

mass number	77
neutron number	40
Relative Atomic Mass	76.930401599 ± 0.0000014 Da
g-factor	0.43622666666667 ± 0.000013333333333333
natural abundance
radioactivitas	☢️ radioactive element
half-life	3.78 ± 0.04 m
Volubilitas	3/2
nuclear quadrupole moment	0.84 ± 0.17
repertus	1972
parity	-

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

⁷⁸Rb

mass number	78
neutron number	41
Relative Atomic Mass	77.928141866 ± 0.000003475 Da
g-factor	0
natural abundance
radioactivitas	☢️ radioactive element
half-life	17.66 ± 0.03 m
Volubilitas	0
nuclear quadrupole moment	0
repertus	1968
parity	+

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

⁷⁹Rb

mass number	79
neutron number	42
Relative Atomic Mass	78.923990095 ± 0.000002085 Da
g-factor	1.34292 ± 0.00048
natural abundance
radioactivitas	☢️ radioactive element
half-life	22.9 ± 0.5 m
Volubilitas	5/2
nuclear quadrupole moment	-0.12 ± 0.04
repertus	1957
parity	+

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

⁸⁰Rb

mass number	80
neutron number	43
Relative Atomic Mass	79.922516442 ± 0.000002 Da
g-factor	-0.0833 ± 0.0007
natural abundance
radioactivitas	☢️ radioactive element
half-life	33.4 ± 0.7 s
Volubilitas	1
nuclear quadrupole moment	0.42 ± 0.08
repertus	1961
parity	+

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

⁸¹Rb

mass number	81
neutron number	44
Relative Atomic Mass	80.9189939 ± 0.000005265 Da
g-factor	1.3727333333333 ± 0.00093333333333333
natural abundance
radioactivitas	☢️ radioactive element
half-life	4.572 ± 0.004 h
Volubilitas	3/2
nuclear quadrupole moment	0.48 ± 0.1
repertus	1949
parity	-

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

⁸²Rb

mass number	82
neutron number	45
Relative Atomic Mass	81.918209023 ± 0.00000323 Da
g-factor	0.554403 ± 0.000016
natural abundance
radioactivitas	☢️ radioactive element
half-life	1.2575 ± 0.0002 m
Volubilitas	1
nuclear quadrupole moment	0.23 ± 0.1
repertus	1949
parity	+

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

⁸³Rb

mass number	83
neutron number	46
Relative Atomic Mass	82.915114181 ± 0.0000025 Da
g-factor	0.56984 ± 0.00032
natural abundance
radioactivitas	☢️ radioactive element
half-life	86.2 ± 0.1 d
Volubilitas	5/2
nuclear quadrupole moment	0.24 ± 0.05
repertus	1950
parity	-

decay mode	intensity
ϵ (electron capture)	100%

⁸⁴Rb

mass number	84
neutron number	47
Relative Atomic Mass	83.914375223 ± 0.000002355 Da
g-factor	-0.6625 ± 0.001
natural abundance
radioactivitas	☢️ radioactive element
half-life	32.82 ± 0.07 d
Volubilitas	2
nuclear quadrupole moment	-0.02 ± 0.04
repertus	1947
parity	-

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	96.1%
β⁻ (β⁻ decay)	3.9%

⁸⁵Rb

mass number	85
neutron number	48
Relative Atomic Mass	84.91178973604 ± 0.00000000537 Da
g-factor	0.541224 ± 0.000016
natural abundance	72.17 ± 0.02
radioactivitas	stable isotope
half-life	Not Radioactive ☢️
Volubilitas	5/2
nuclear quadrupole moment	0.276 ± 0.001
repertus	1921
parity	-

⁸⁶Rb

mass number	86
neutron number	49
Relative Atomic Mass	85.911167443 ± 0.000000214 Da
g-factor	-0.8487 ± 0.0008
natural abundance
radioactivitas	☢️ radioactive element
half-life	18.645 ± 0.008 d
Volubilitas	2
nuclear quadrupole moment	0.23 ± 0.06
repertus	1941
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%
ϵ (electron capture)	0.0052%

⁸⁷Rb

mass number	87
neutron number	50
Relative Atomic Mass	86.909180529 ± 0.000000006 Da
g-factor	1.8341933333333 ± 0.000053333333333333
natural abundance	27.83 ± 0.02
radioactivitas	☢️ radioactive element
half-life	49.7 ± 0.3 Gy
Volubilitas	3/2
nuclear quadrupole moment	0.1335 ± 0.0005
repertus	1921
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%

⁸⁸Rb

mass number	88
neutron number	51
Relative Atomic Mass	87.91131559 ± 0.00000017 Da
g-factor	0.253755 ± 0.00001
natural abundance
radioactivitas	☢️ radioactive element
half-life	17.78 ± 0.03 m
Volubilitas	2
nuclear quadrupole moment	-0.01 ± 0.11
repertus	1939
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%

⁸⁹Rb

mass number	89
neutron number	52
Relative Atomic Mass	88.912278136 ± 0.000005825 Da
g-factor	1.5887333333333 ± 0.00046666666666667
natural abundance
radioactivitas	☢️ radioactive element
half-life	15.32 ± 0.1 m
Volubilitas	3/2
nuclear quadrupole moment	0.17 ± 0.03
repertus	1940
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%

⁹⁰Rb

mass number	90
neutron number	53
Relative Atomic Mass	89.914797557 ± 0.000006926 Da
g-factor	0
natural abundance
radioactivitas	☢️ radioactive element
half-life	158 ± 5 s
Volubilitas	0
nuclear quadrupole moment	0
repertus	1951
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%

⁹¹Rb

mass number	91
neutron number	54
Relative Atomic Mass	90.916537261 ± 0.000008375 Da
g-factor	1.4540666666667 ± 0.001
natural abundance
radioactivitas	☢️ radioactive element
half-life	58.2 ± 0.3 s
Volubilitas	3/2
nuclear quadrupole moment	0.19 ± 0.05
repertus	1951
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)

⁹²Rb

mass number	92
neutron number	55
Relative Atomic Mass	91.919728477 ± 0.000006573 Da
g-factor	0
natural abundance
radioactivitas	☢️ radioactive element
half-life	4.48 ± 0.03 s
Volubilitas	0
nuclear quadrupole moment	0
repertus	1960
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	0.0107%

⁹³Rb

mass number	93
neutron number	56
Relative Atomic Mass	92.922039334 ± 0.000008406 Da
g-factor	0.56368 ± 0.00064
natural abundance
radioactivitas	☢️ radioactive element
half-life	5.84 ± 0.02 s
Volubilitas	5/2
nuclear quadrupole moment	0.21 ± 0.06
repertus	1960
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	1.39%

⁹⁴Rb

mass number	94
neutron number	57
Relative Atomic Mass	93.926394819 ± 0.000002177 Da
g-factor	0.49936666666667 ± 0.0006
natural abundance
radioactivitas	☢️ radioactive element
half-life	2.702 ± 0.005 s
Volubilitas	3
nuclear quadrupole moment	0.2 ± 0.07
repertus	1961
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	10.3%

⁹⁵Rb

mass number	95
neutron number	58
Relative Atomic Mass	94.929263849 ± 0.000021733 Da
g-factor	0.5332 ± 0.0012
natural abundance
radioactivitas	☢️ radioactive element
half-life	377.7 ± 0.8 ms
Volubilitas	5/2
nuclear quadrupole moment	0.26 ± 0.09
repertus	1967
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	8.7%

⁹⁶Rb

mass number	96
neutron number	59
Relative Atomic Mass	95.934133398 ± 0.000003599 Da
g-factor	0.73275 ± 0.00085
natural abundance
radioactivitas	☢️ radioactive element
half-life	201.5 ± 0.9 ms
Volubilitas	2
nuclear quadrupole moment	0.3 ± 0.09
repertus	1967
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	13.7%
2n (2-neutron emission)

⁹⁷Rb

mass number	97
neutron number	60
Relative Atomic Mass	96.937177117 ± 0.000002052 Da
g-factor	1.2266666666667 ± 0.0013333333333333
natural abundance
radioactivitas	☢️ radioactive element
half-life	169.1 ± 0.6 ms
Volubilitas	3/2
nuclear quadrupole moment	0.7
repertus	1969
parity	+

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	25.5%
2n (2-neutron emission)

⁹⁸Rb

mass number	98
neutron number	61
Relative Atomic Mass	97.941632317 ± 0.000017265 Da
g-factor	0
natural abundance
radioactivitas	☢️ radioactive element
half-life	115 ± 6 ms
Volubilitas	0
nuclear quadrupole moment	0
repertus	1971
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	14.3%
2n (2-neutron emission)	0.054%

⁹⁹Rb

mass number	99
neutron number	62
Relative Atomic Mass	98.94511919 ± 0.000004327 Da
g-factor
natural abundance
radioactivitas	☢️ radioactive element
half-life	54 ± 4 ms
Volubilitas	3/2
nuclear quadrupole moment
repertus	1971
parity	+

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	17.3%
2n (2-neutron emission)

¹⁰⁰Rb

mass number	100
neutron number	63
Relative Atomic Mass	99.950331532 ± 0.000014089 Da
g-factor
natural abundance
radioactivitas	☢️ radioactive element
half-life	51.3 ± 1.6 ms
Volubilitas	4
nuclear quadrupole moment
repertus	1978
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	5.6%
2n (2-neutron emission)	0.15%

¹⁰¹Rb

mass number	101
neutron number	64
Relative Atomic Mass	100.954302 ± 0.000022 Da
g-factor
natural abundance
radioactivitas	☢️ radioactive element
half-life	31.8 ± 3.3 ms
Volubilitas	3/2
nuclear quadrupole moment
repertus	1992
parity	+

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	28%
2n (2-neutron emission)

¹⁰²Rb

mass number	102
neutron number	65
Relative Atomic Mass	101.960008 ± 0.000089 Da
g-factor
natural abundance
radioactivitas	☢️ radioactive element
half-life	37 ± 4 ms
Volubilitas	4
nuclear quadrupole moment
repertus	1995
parity	+

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	65%
2n (2-neutron emission)

¹⁰³Rb

mass number	103
neutron number	66
Relative Atomic Mass	102.964401 ± 0.000429 Da
g-factor
natural abundance
radioactivitas	☢️ radioactive element
half-life	26 ± 11 ms
Volubilitas	3/2
nuclear quadrupole moment
repertus	2010
parity	+

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)
2n (2-neutron emission)

¹⁰⁴Rb

mass number	104
neutron number	67
Relative Atomic Mass	103.970531 ± 0.000537 Da
g-factor
natural abundance
radioactivitas	☢️ radioactive element
half-life
Volubilitas
nuclear quadrupole moment
repertus	2018
parity

decay mode	intensity
β⁻ (β⁻ decay)
β⁻ n (β⁻-delayed neutron emission)
2n (2-neutron emission)

historia

inventor	R. Bunsen, G. Kirchoff
location of discovery	Germany
repertus	1861
Etymologia	Latin: rubidus (deep red); the color its salts impart to flames.
pronunciation	roo-BID-i-em (English)

source

Abundance
Abundance in Earth's crust	90 mg/kg
natural abundance (Oceanus)	0.12 mg/L
natural abundance (Corpus humanum)	0.00046 %
natural abundance (Meteoroides)	0.00032 %
natural abundance (Sol)	0.000003 %
Abundance in Universe	0.000001 %

Nuclear Screening Constants

1	s	0.7922
2	p	3.9612
2	s	9.8432
3	d	15.3208
3	p	15.6967
3	s	15.1573
4	p	26.1192
4	s	24.612
5	s	32.0155

Rubidium on ChemicalAid

Rubidium (Rb)

Physical Property

Chemical Property

other

Isotopes of Rubidium

71Rb

72Rb

73Rb

74Rb

75Rb

76Rb

77Rb

78Rb

79Rb

80Rb

81Rb

82Rb

83Rb

84Rb

85Rb

86Rb

87Rb

88Rb

89Rb

90Rb

91Rb

92Rb

93Rb

94Rb

95Rb

96Rb

97Rb

98Rb

99Rb

100Rb

101Rb

102Rb

103Rb

104Rb

historia

source

Nuclear Screening Constants

⁷¹Rb

⁷²Rb

⁷³Rb

⁷⁴Rb

⁷⁵Rb

⁷⁶Rb

⁷⁷Rb

⁷⁸Rb

⁷⁹Rb

⁸⁰Rb

⁸¹Rb

⁸²Rb

⁸³Rb

⁸⁴Rb

⁸⁵Rb

⁸⁶Rb

⁸⁷Rb

⁸⁸Rb

⁸⁹Rb

⁹⁰Rb

⁹¹Rb

⁹²Rb

⁹³Rb

⁹⁴Rb

⁹⁵Rb

⁹⁶Rb

⁹⁷Rb

⁹⁸Rb

⁹⁹Rb

¹⁰⁰Rb

¹⁰¹Rb

¹⁰²Rb

¹⁰³Rb

¹⁰⁴Rb