Barium (Ba)

Barium is the 56th element in the periodic table and has a symbol of Ba and atomic number of 56. It has an atomic weight of 137.327 and a mass number of 138. Barium has fifty-six protons and eighty-two neutrons in its nucleus, and fifty-six electrons in six shells. It is located in group two, period six and block s of the periodic table. Silvery-white reactive element, belonging to group 2 of the periodic table. Soluble barium compounds are extremely poisonous. Identified in 1774 by Karl Scheele and extracted in 1808 by Humphry Davy.

Atomic Number	56
Atomic Weight	137.327
Mass Number	138

Group	2
Period	6
Block	s

Protons	56 p⁺
Neutrons	82 n⁰
Electrons	56 e^-

Properties

Physical Properties
Atomic Radius	215 pm 293 pm
Molar Volume	39 cm³/mol
Covalent Radius	196 pm 161 pm 149 pm 210 pm 215 pm
Metallic Radius	198 pm 222 pm
Ionic Radius	135 pm 138 pm 142 pm 147 pm 152 pm 157 pm 161 pm
Crystal Radius	149 pm 152 pm 156 pm 161 pm 166 pm 171 pm 175 pm
Van der Waals Radius	270 pm 268 pm 307 pm 268 pm 370.3 pm
Density	3.62 g/cm³ 3,338 kg/m³
Energy
Proton Affinity
Electron Affinity	0.14462 eV/particle
Ionization Energy	5.211664 eV/particle 10.003826 eV/particle 35.84 eV/particle 47.03 eV/particle 58 eV/particle 71 eV/particle 86 eV/particle 101 eV/particle 130.53 eV/particle 146.52 eV/particle 241 eV/particle 267.1 eV/particle 296 eV/particle 325 eV/particle 354 eV/particle 390 eV/particle 422 eV/particle 455 eV/particle 488 eV/particle 520 eV/particle 646 eV/particle 679 eV/particle 717 eV/particle 752 eV/particle 809 eV/particle 846 eV/particle 935 eV/particle 976.6 eV/particle 1,695 eV/particle 1,776 eV/particle 1,864 eV/particle 1,958 eV/particle 2,047 eV/particle 2,142 eV/particle 2,256 eV/particle 2,349 eV/particle 2,452 eV/particle 2,547 eV/particle 2,814 eV/particle 2,901 eV/particle 2,994 eV/particle 3,081 eV/particle 3,266 eV/particle 3,363 eV/particle 3,550 eV/particle 3,640 eV/particle 8,326 eV/particle 8,565 eV/particle 8,831 eV/particle 9,077 eV/particle 9,739 eV/particle 10,023 eV/particle 10,376 eV/particle 10,616.42 eV/particle 43,485.364 eV/particle 44,561.47 eV/particle

Heat of Vaporization	142 kJ/mol
Heat of Fusion	7.66 kJ/mol
Heat of Formation	179.1 kJ/mol
Electrons
Electron Shells	2, 8, 18, 18, 8, 2

Valence Electrons	2 ⓘ

Electron Configuration	[Xe] 6s²ⓘ 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s²

Oxidation States	1, 2
Electronegativity	5.211 eV/particle 0.1586786 0.89
Electrophilicity Index	0.7077543210759566 eV/particle
States of Matter
Phase	Solid
Gas Phase
Boiling Point	2,118.15 K
Melting Point	1,000.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Barium is a Silver. Ba has a CPK of #ffa500, Jmol of #00c900, and MOLCAS GV of #00c900.
Color	Silver #ffa500 #00c900 #00c900
Appearance
Refractive Index
Thermodynamic Properties
Thermal Conductivity
Thermal Expansion	0.0000206 1/K
Molar Heat Capacity	28.07 J/(mol K)
Specific Heat Capacity	0.204 J/(g⋅K)
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
Type	Conductor
Electrical Conductivity	2.9 MS/m
Electrical Resistivity	0.00000035 m Ω
Superconducting Point
Magnetism
Type	paramagnetic
Magnetic Susceptibility (Mass)	0.0000000113 m³/Kg
Magnetic Susceptibility (Molar)	0.000000001552 m³/mol
Magnetic Susceptibility (Volume)	0.00003966
Magnetic Ordering
Curie Point
Neel Point
Structure
The Crystal Structure of Barium is BCC. The lattice constant of Ba is 5.02 Å. The lattice angles of Element 56 are π/2, π/2, π/2.
Crystal Structure	Body Centered Cubic (BCC)
Lattice Constant	5.02 Å
Lattice Angles	π/2, π/2, π/2
Mechanical Properties
Barium has a Mohs hardness of 1.25 MPa. The Bulk Modulus of Ba is 9.6 GPa. The Shear Modulus of Element 56 is 4.9 GPa. The Young Modulus of Barium (Ba) is 13 GPa. The Speed of Sound of Barium is 1620 m/s.
Hardness	1.25 MPa
Bulk Modulus	9.6 GPa
Shear Modulus	4.9 GPa
Young's Modulus	13 GPa
Poisson Ratio
Speed of Sound	1,620 m/s
Classification
The CAS Group of Barium is IIA. The IUPAC Group of Ba is IIA. The Glawe Number of Element 56 is 14. The Mendeleev Number of Barium (Ba) is 9. The Pettifor Number of Barium is 14. The Geochemical Class of Ba is alkaline earth metal. The Goldschmidt Class of Element 56 is litophile.
Category	Alkaline earth metals, Alkaline earth metals
CAS Group	IIA
IUPAC Group	IIA
Glawe Number	14
Mendeleev Number	9
Pettifor Number	14
Geochemical Class	alkaline earth metal
Goldschmidt Class	litophile
Other
The Dipole Polarizability of Barium is 272 plus or minus 10 a₀. Ba has a C6 Dispersion Coefficient (GB) of 5540 a₀. The Allotropes of Element 56 is . The Neutron Cross Section of Barium (Ba) is 1.3. The Neutron Mass Absorption of Barium is 0.00027. The Quantum Numbers of Ba is 1S0. The Space Group of Element 56 is 229 (Im_3m).
Gas Basicity
Dipole Polarizability	272 ± 10 a₀
C6 Dispersion Coefficient	5,540 a₀
Allotropes
Neutron Cross Section	1.3
Neutron Mass Absorption	0.00027
Quantum Numbers	1S0
Space Group	229 (Im_3m)

Isotopes of Barium

Stable Isotopes	5
Unstable Isotopes	37
Radioactive Isotopes	37

¹¹³Ba

Mass Number	113
Neutron Number	57
Relative Atomic Mass	112.95737 ± 0.000322 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life
Spin	5/2
Quadrupole Moment
Discovery Year
Parity	+

Decay Mode	Intensity
p (proton emission)
α (α emission)

¹¹⁴Ba

Mass Number	114
Neutron Number	58
Relative Atomic Mass	113.950718489 ± 0.000110227 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	460 ± 125 ms
Spin	0
Quadrupole Moment	0
Discovery Year	1995
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	20%
α (α emission)	0.9%
12C	0.0034%

¹¹⁵Ba

Mass Number	115
Neutron Number	59
Relative Atomic Mass	114.947482 ± 0.000215 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	450 ± 50 ms
Spin	5/2
Quadrupole Moment
Discovery Year	1997
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	15%

¹¹⁶Ba

Mass Number	116
Neutron Number	60
Relative Atomic Mass	115.941621 ± 0.000215 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	1.3 ± 0.2 s
Spin	0
Quadrupole Moment	0
Discovery Year	1997
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	3%

¹¹⁷Ba

Mass Number	117
Neutron Number	61
Relative Atomic Mass	116.938316403 ± 0.000268749 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	1.75 ± 0.07 s
Spin	3/2
Quadrupole Moment
Discovery Year	1977
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	13%
β⁺α (β⁺-delayed α emission)	0.024%

¹¹⁸Ba

Mass Number	118
Neutron Number	62
Relative Atomic Mass	117.933226 ± 0.000215 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	5.2 ± 0.2 s
Spin	0
Quadrupole Moment	0
Discovery Year	1997
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹¹⁹Ba

Mass Number	119
Neutron Number	63
Relative Atomic Mass	118.930659683 ± 0.000214997 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	5.4 ± 0.3 s
Spin	5/2
Quadrupole Moment
Discovery Year	1974
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	25%

¹²⁰Ba

Mass Number	120
Neutron Number	64
Relative Atomic Mass	119.926044997 ± 0.000322241 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	24 ± 2 s
Spin	0
Quadrupole Moment	0
Discovery Year	1974
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹²¹Ba

Mass Number	121
Neutron Number	65
Relative Atomic Mass	120.924052286 ± 0.000152333 Da
G-Factor	0.264 ± 0.0004
Abundance
Radioactivity	☢️ Radioactive
Half Life	29.7 ± 1.5 s
Spin	5/2
Quadrupole Moment	1.89 ± 0.13
Discovery Year	1975
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	0.02%

¹²²Ba

Mass Number	122
Neutron Number	66
Relative Atomic Mass	121.919904 ± 0.00003 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	1.95 ± 0.15 m
Spin	0
Quadrupole Moment	0
Discovery Year	1974
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹²³Ba

Mass Number	123
Neutron Number	67
Relative Atomic Mass	122.91878106 ± 0.000013 Da
G-Factor	-0.272 ± 0.0004
Abundance
Radioactivity	☢️ Radioactive
Half Life	2.7 ± 0.4 m
Spin	5/2
Quadrupole Moment	1.57 ± 0.13
Discovery Year	1962
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹²⁴Ba

Mass Number	124
Neutron Number	68
Relative Atomic Mass	123.915093627 ± 0.000013416 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	11 ± 0.5 m
Spin	0
Quadrupole Moment	0
Discovery Year	1967
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹²⁵Ba

Mass Number	125
Neutron Number	69
Relative Atomic Mass	124.91447184 ± 0.0000118 Da
G-Factor	0.354 ± 0.024
Abundance
Radioactivity	☢️ Radioactive
Half Life	3.3 ± 0.3 m
Spin	1/2
Quadrupole Moment	0
Discovery Year	1968
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹²⁶Ba

Mass Number	126
Neutron Number	70
Relative Atomic Mass	125.911250202 ± 0.000013416 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	100 ± 2 m
Spin	0
Quadrupole Moment	0
Discovery Year	1954
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹²⁷Ba

Mass Number	127
Neutron Number	71
Relative Atomic Mass	126.911091272 ± 0.000012192 Da
G-Factor	0.1668 ± 0.002
Abundance
Radioactivity	☢️ Radioactive
Half Life	12.7 ± 0.4 m
Spin	1/2
Quadrupole Moment	0
Discovery Year	1952
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹²⁸Ba

Mass Number	128
Neutron Number	72
Relative Atomic Mass	127.908352446 ± 0.000001728 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	2.43 ± 0.05 d
Spin	0
Quadrupole Moment	0
Discovery Year	1950
Parity	+

Decay Mode	Intensity
ϵ (electron capture)	100%

¹²⁹Ba

Mass Number	129
Neutron Number	73
Relative Atomic Mass	128.908683409 ± 0.000011276 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	2.23 ± 0.11 h
Spin	1/2
Quadrupole Moment	0
Discovery Year	1950
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹³⁰Ba

Mass Number	130
Neutron Number	74
Relative Atomic Mass	129.906326002 ± 0.000000308 Da
G-Factor	0
Abundance	0.11 ± 0.01
Radioactivity	☢️ Radioactive
Half Life
Spin	0
Quadrupole Moment	0
Discovery Year	1936
Parity	+

Decay Mode	Intensity
2β⁺ (double β⁺ decay)

¹³¹Ba

Mass Number	131
Neutron Number	75
Relative Atomic Mass	130.906946315 ± 0.000000445 Da
G-Factor	1.4166 ± 0.0004
Abundance
Radioactivity	☢️ Radioactive
Half Life	11.52 ± 0.01 d
Spin	1/2
Quadrupole Moment	0
Discovery Year	1947
Parity	+

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹³²Ba

Mass Number	132
Neutron Number	76
Relative Atomic Mass	131.905061231 ± 0.00000113 Da
G-Factor	0
Abundance	0.1 ± 0.01
Radioactivity	☢️ Radioactive
Half Life
Spin	0
Quadrupole Moment	0
Discovery Year	1936
Parity	+

Decay Mode	Intensity
2β⁺ (double β⁺ decay)

¹³³Ba

Mass Number	133
Neutron Number	77
Relative Atomic Mass	132.906007443 ± 0.000001065 Da
G-Factor	1.5438 ± 0.0004
Abundance
Radioactivity	☢️ Radioactive
Half Life	10.5379 ± 0.0016 y
Spin	1/2
Quadrupole Moment	0
Discovery Year	1941
Parity	+

Decay Mode	Intensity
ϵ (electron capture)	100%

¹³⁴Ba

Mass Number	134
Neutron Number	78
Relative Atomic Mass	133.904508249 ± 0.000000269 Da
G-Factor	0
Abundance	2.42 ± 0.15
Radioactivity	Stable
Half Life	Not Radioactive ☢️
Spin	0
Quadrupole Moment	0
Discovery Year	1936
Parity	+

¹³⁵Ba

Mass Number	135
Neutron Number	79
Relative Atomic Mass	134.905688447 ± 0.000000263 Da
G-Factor	0.55873333333333 ± 0.00013333333333333
Abundance	6.59 ± 0.1
Radioactivity	Stable
Half Life	Not Radioactive ☢️
Spin	3/2
Quadrupole Moment	0.153 ± 0.002
Discovery Year	1932
Parity	+

¹³⁶Ba

Mass Number	136
Neutron Number	80
Relative Atomic Mass	135.9045758 ± 0.000000262 Da
G-Factor	0
Abundance	7.85 ± 0.24
Radioactivity	Stable
Half Life	Not Radioactive ☢️
Spin	0
Quadrupole Moment	0
Discovery Year	1932
Parity	+

¹³⁷Ba

Mass Number	137
Neutron Number	81
Relative Atomic Mass	136.905827207 ± 0.000000266 Da
G-Factor	0.625 ± 0.00013333333333333
Abundance	11.23 ± 0.23
Radioactivity	Stable
Half Life	Not Radioactive ☢️
Spin	3/2
Quadrupole Moment	0.236 ± 0.003
Discovery Year	1932
Parity	+

¹³⁸Ba

Mass Number	138
Neutron Number	82
Relative Atomic Mass	137.905247059 ± 0.000000267 Da
G-Factor	0
Abundance	71.7 ± 0.29
Radioactivity	Stable
Half Life	Not Radioactive ☢️
Spin	0
Quadrupole Moment	0
Discovery Year	1925
Parity	+

¹³⁹Ba

Mass Number	139
Neutron Number	83
Relative Atomic Mass	138.908841164 ± 0.000000271 Da
G-Factor	-0.278 ± 0.0014285714285714
Abundance
Radioactivity	☢️ Radioactive
Half Life	82.93 ± 0.09 m
Spin	7/2
Quadrupole Moment	-0.552 ± 0.013
Discovery Year	1937
Parity	-

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁴⁰Ba

Mass Number	140
Neutron Number	84
Relative Atomic Mass	139.910608231 ± 0.00000848 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	12.7534 ± 0.0021 d
Spin	0
Quadrupole Moment	0
Discovery Year	1939
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁴¹Ba

Mass Number	141
Neutron Number	85
Relative Atomic Mass	140.914403653 ± 0.000005709 Da
G-Factor	-0.22466666666667 ± 0.0033333333333333
Abundance
Radioactivity	☢️ Radioactive
Half Life	18.27 ± 0.07 m
Spin	3/2
Quadrupole Moment	0.437 ± 0.01
Discovery Year	1945
Parity	-

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁴²Ba

Mass Number	142
Neutron Number	86
Relative Atomic Mass	141.916432904 ± 0.000006355 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	10.6 ± 0.2 m
Spin	0
Quadrupole Moment	0
Discovery Year	1959
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁴³Ba

Mass Number	143
Neutron Number	87
Relative Atomic Mass	142.920625149 ± 0.000007253 Da
G-Factor	0.1772 ± 0.0044
Abundance
Radioactivity	☢️ Radioactive
Half Life	14.5 ± 0.3 s
Spin	5/2
Quadrupole Moment	-0.85 ± 0.02
Discovery Year	1962
Parity	-

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁴⁴Ba

Mass Number	144
Neutron Number	88
Relative Atomic Mass	143.922954821 ± 0.000007661 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	11.73 ± 0.08 s
Spin	0
Quadrupole Moment	0
Discovery Year	1967
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁴⁵Ba

Mass Number	145
Neutron Number	89
Relative Atomic Mass	144.9275184 ± 0.0000091 Da
G-Factor	-0.114 ± 0.0028
Abundance
Radioactivity	☢️ Radioactive
Half Life	4.31 ± 0.16 s
Spin	5/2
Quadrupole Moment	1.18 ± 0.02
Discovery Year	1974
Parity	-

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁴⁶Ba

Mass Number	146
Neutron Number	90
Relative Atomic Mass	145.9303632 ± 0.0000019 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	2.15 ± 0.04 s
Spin	0
Quadrupole Moment	0
Discovery Year	1970
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁴⁷Ba

Mass Number	147
Neutron Number	91
Relative Atomic Mass	146.9353039 ± 0.0000212 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	893 ± 1 ms
Spin	5/2
Quadrupole Moment
Discovery Year	1978
Parity	-

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	0.07%

¹⁴⁸Ba

Mass Number	148
Neutron Number	92
Relative Atomic Mass	147.938223 ± 0.0000016 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	620 ± 5 ms
Spin	0
Quadrupole Moment	0
Discovery Year	1979
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	0.4%

¹⁴⁹Ba

Mass Number	149
Neutron Number	93
Relative Atomic Mass	148.943284 ± 0.0000027 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	349 ± 4 ms
Spin	3/2
Quadrupole Moment
Discovery Year	1993
Parity	-

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	3.9%

¹⁵⁰Ba

Mass Number	150
Neutron Number	94
Relative Atomic Mass	149.9464411 ± 0.0000061 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	258 ± 5 ms
Spin	0
Quadrupole Moment	0
Discovery Year	1994
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	1%

¹⁵¹Ba

Mass Number	151
Neutron Number	95
Relative Atomic Mass	150.951755 ± 0.000429 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	167 ± 5 ms
Spin	3/2
Quadrupole Moment
Discovery Year	1994
Parity	-

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)

¹⁵²Ba

Mass Number	152
Neutron Number	96
Relative Atomic Mass	151.95533 ± 0.000429 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	139 ± 8 ms
Spin	0
Quadrupole Moment	0
Discovery Year	2010
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)

¹⁵³Ba

Mass Number	153
Neutron Number	97
Relative Atomic Mass	152.960848 ± 0.000429 Da
G-Factor
Abundance
Radioactivity	☢️ Radioactive
Half Life	113 ± 39 ms
Spin	5/2
Quadrupole Moment
Discovery Year	2016
Parity	-

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)
2n (2-neutron emission)

¹⁵⁴Ba

Mass Number	154
Neutron Number	98
Relative Atomic Mass	153.964659 ± 0.000537 Da
G-Factor	0
Abundance
Radioactivity	☢️ Radioactive
Half Life	53 ± 48 ms
Spin	0
Quadrupole Moment	0
Discovery Year	2017
Parity	+

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

History

Barium was identified as a new element in 1774 by Carl Wilhelm Scheele. Barium was first isolated by electrolysis of molten barium salts in 1808, by Sir Humphry Davy in England. Robert Bunsen and Augustus Matthiessen obtained pure barium by electrolysis of a molten mixture of barium chloride and ammonium chloride. From the Greek word barys, heavy

Discoverers	Sir Humphrey Davy
Discovery Location	England
Discovery Year	1808
Etymology (Name Origin)	Greek: barys (heavy or dense).
Pronunciation	BAR-i-em (English)

Water-soluble barium compounds are poisonous

At low doses, barium acts as a muscle stimulant

Uses

Barium is used as a flashed getter in vacuum tubes to remove the last traces of gases. It is often used in barium-nickel alloys for spark plug wire. Barium sulfate is important to the petroleum industry as a drilling fluid in oil and gas wells. Barium is also used in medicine to detect abnormalities in the digestive system. Barite, or barium sulfate (BaSO4), when ground is used as a filter for rubber, plastics, and resins. It is insoluable in water and so is used in X-rays of the digestive system. Barium nitrate, Ba(NO3)2, burns brilliant green and is used in fireworks.

Sources

Found in barytine (BaSO4) and witherite (BaCO3), never found in pure form due to its reactivity. Must be stored under kerosene to remain pure.

Abundance
Abundance in Earth's crust	425 mg/kg
Natural Abundance (Oceans)	0.013 mg/L
Natural Abundance (Human Body)	0.00003 %
Natural Abundance (Meteor)	0.00027 %
Natural Abundance (Sun)	0.000001 %
Abundance in Universe	0.000001 %

Nuclear Screening Constants

1	s	1.1139
2	p	4.1904
2	s	14.7532
3	d	13.9757
3	p	18.6836
3	s	18.8444
4	d	32.216
4	p	29.1968
4	s	28.08
5	p	41.1995
5	s	39.3805
6	s	48.425

Also Known As

Ba
element 56
56Ba

Translations

Norwegian Bokmålbarium
Frenchbaryum
Italianbario
Norwegian Nynorskbarium
Danishbarium
Swedishbarium
GermanBarium
Hungarianbárium
Afrikaansbarium
Amharicባሪየም
AragoneseBario
Arabicباريوم
AzerbaijaniBarium
BelarusianБарый
Bulgarianбарий
Banglaবেরিয়াম
BretonBariom
Bosnianbarij
Catalanbari
CherokeeᏇᎵᎥᎻ
CorsicanBariu
Czechbaryum
ChuvashБари
WelshBariwm
Greekβάριο
Esperantobario
Spanishbario
Estonianbaarium
Basquebario
Persianباریم
Finnishbarium
FriulianBari
IrishBairiam
GalicianBario
ManxBaarium
Hakka Chinesebarium
Hebrewבריום
Hindiबेरियम
Fiji HindiBarium
Croatianbarij
Haitian CreoleBaryòm
Armenianբարիում
Interlinguabarium
Indonesianbarium
Idobario
Icelandicbarín
Japaneseバリウム
Lojbantijyjinme
JavaneseBarium
Georgianბარიუმი
KazakhБарий
Kannadaಬೇರಿಯಮ್
Korean바륨
KurdishBaryûm
KomiБарий
Latinbarium
LuxembourgishBarium
LigurianBario
Lithuanianbaris
Latvianbārijs
Maorikonu-okehu
Malayalamബേരിയം
Mongolianбари
Marathiबेरियम
Western MariБарий
MalayBarium
Burmeseဘေရီယမ်
Low GermanBarium
Dutchbarium
OccitanBari
Polishbar
pnbبیریم
Portuguesebário
QuechuaBaryu
Romanianbariu
Russianбарий
SakhaБариум
Sicilianbariu
Serbo-CroatianBarijum
Slovakbárium
Slovenianbarij
Serbianбаријум
Saterland FrisianBarium
SwahiliBari
Tamilபேரியம்
Thaiแบเรียม
TagalogBaryo
Turkishbaryum
Uyghurبارىي
Ukrainianбарій
Urduبیریئم
VepsBarii
Vietnamesebari
WarayBaryo
KalmykБариум
Yiddishבאריום
YorubaBarium
Chinese鋇
German (Switzerland)Barium
English (Canada)Barium
English (United Kingdom)barium
Portuguese (Brazil)bário
Cantonese鋇
Central Kurdishباریۆم
Punjabiਬੇਰੀਅਮ
CebuanoBaryo
Macedonianбариум
Odiaବ୍ୟାରିଅମ
Gujaratiબેરિયમ
TatarБарий
PiedmonteseBario
Belarusian (Taraskievica orthography)Бар
SomaliBaariyaam
AlbanianBariumi
UzbekBariy
AromanianBariu
KyrgyzБарий
LimburgishBarium
FaroeseBarium
Nepaliबेरियम
Teluguబేరియం
Sanskritबेरियम
Maltesebarju
LombardBario
Scottish GaelicBarium
Bhojpuriबेरियम
Paliबेरियम
Newariबेरियम
Gan Chinese鋇
cdoBarium
Min Nan ChineseBarium
Tibetanབྷེ་རིམ།
AsturianBariu
TajikБарий
Literary Chinese鋇
Wu Chinese钡
kbpParɩyɔm
Lingua Franca Novabario
oloBarii
OsseticБари
Northern FrisianBaarium
Chinese (Traditional)鋇
Chinese (Taiwan)鋇
Chinese (Simplified)钡
SardinianBàriu
BashkirБарий
Moroccan Arabicباريوم
Egyptian Arabicباريوم
Pashtoبېريوم
bclBaryo (elemento)
CornishBariom
MinangkabauBarium
BalineseBarium
Chinese (Hong Kong SAR China)鋇
GandaBariyaamu
Kashmiriبیرِیَم
WalloonBariom
ZuluUmBhanya

Barium on ChemicalAid

Art & Architecture Thesaurus ID	300311585
Australian Educational Vocabulary ID	scot/2246
BNCF Thesaurus ID	31174
Biblioteca Nacional de España ID	XX540454
Bibliothèque nationale de France ID	12203013v
Brockhaus Enzyklopädie online ID	barium
CAB ID	18806
CA PROP 65 ID	barium
CAS Registry Number	7440-39-3
CPV Supplementary	AA32
ChEBI ID	32595
ChemSpider ID	4511436
Common Procurement Vocabulary	14765000
DSSTOX compound identifier	DTXCID80875617
DSSTox substance ID	DTXSID8023894
Den Store Danske ID	barium
DrugBank ID	12481
ECHA Substance Infocard ID	100.028.317
Encyclopædia Britannica Online ID	science/barium
Encyclopædia Universalis ID	baryum
Freebase ID	/m/025svml
French Vikidia ID	Baryum
GND ID	4140300-9
Gran Enciclopèdia Catalana ID	0006437
Great Russian Encyclopedia Online ID	862577
HSDB ID	4481
ICSC ID	1052
InChI	InChI=1S/Ba
InChIKey	DSAJWYNOEDNPEQ-UHFFFAOYSA-N
KBpedia ID	Barium
Krugosvet article	nauka_i_tehnika/himiya/BARI.html
LEM ID	LEM201001269
Library of Congress authority ID	sh85011853
MeSH descriptor ID	D001464
NALT ID	6419
NDL Authority ID	00560541
NE.se ID	barium
NKCR AUT ID	ph163873
Namuwiki ID	바륨
National Library of Israel J9U ID	987007283148305171
National Library of Latvia ID	000302070
OmegaWiki Defined Meaning	310
OpenAlex ID	C542576722
PM20 ware ID	142042
PSH ID	5754
PubChem CID	5355457
Quora topic ID	Barium
RxNorm ID	1311067
Römpp online ID	RD-02-00240
Store medisinske leksikon ID	barium
Store norske leksikon ID	barium
Treccani ID	bario
UK Archival Thesaurus ID	f2/mt225/4347/7670
UK Parliament thesaurus ID	8545
UNII	24GP945V5T
USGS Thesaurus ID	1403
WordNet 3.1 Synset ID	14654176-n
YSO ID	39159
ZVG number	8420

Barium (Ba)

Properties

Isotopes of Barium

113Ba

114Ba

115Ba

116Ba

117Ba

118Ba

119Ba

120Ba

121Ba

122Ba

123Ba

124Ba

125Ba

126Ba

127Ba

128Ba

129Ba

130Ba

131Ba

132Ba

133Ba

134Ba

135Ba

136Ba

137Ba

138Ba

139Ba

140Ba

141Ba

142Ba

143Ba

144Ba

145Ba

146Ba

147Ba

148Ba

149Ba

150Ba

151Ba

152Ba

153Ba

154Ba