Actinium (Ac)

chemical element with the atomic number of 89

Atomic Number	89
Atomic Weight	227
mass number	205

Group	3
Period	7
Block	d

proton	89 p⁺
Neutron	116 n⁰
Elektron	89 e^-

Physical Property

Atomic Radius	195 pm 293 pm
molar volume	22,54 cm³/mol
Covalent Radius	186 pm 153 pm 140 pm 215 pm
Metallic Radius
ionic radius	112 pm 122 pm
Crystal Radius	126 pm 136 pm
Van der Waals radius	247 pm 308 pm 347,8 pm
density	10 g/cm³

Chemical Property

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orka

proton affinity
electron affinity	0,35 eV/particle
ionization energy	5,380226 eV/particle 11,75 eV/particle 17,431 eV/particle 44,8 eV/particle 55 eV/particle 67 eV/particle 79 eV/particle 98,9 eV/particle 113,9 eV/particle 143,9 eV/particle 161,1 eV/particle 233 eV/particle 255 eV/particle 279 eV/particle 305 eV/particle 330 eV/particle 355 eV/particle 390 eV/particle 416 eV/particle 444 eV/particle 470 eV/particle 610 eV/particle 640 eV/particle 670 eV/particle 710 eV/particle 780 eV/particle 820 eV/particle 920 eV/particle 950 eV/particle 1.030 eV/particle 1.100 eV/particle 1.170 eV/particle 1.240 eV/particle 1.310 eV/particle 1.380 eV/particle 1.460 eV/particle 1.530 eV/particle 1.610 eV/particle 1.680 eV/particle 1.750 eV/particle 1.820 eV/particle 1.900 eV/particle 1.970 eV/particle 2.298 eV/particle 2.362 eV/particle 2.430 eV/particle 2.503 eV/particle 2.572 eV/particle 2.639 eV/particle 2.762 eV/particle 2.833 eV/particle 2.908 eV/particle 2.980 eV/particle 3.264 eV/particle 3.334 eV/particle 3.409 eV/particle 3.479 eV/particle 3.811 eV/particle 3.893 eV/particle 4.093 eV/particle 4.175 eV/particle 6.767 eV/particle 6.923 eV/particle 7.088 eV/particle 7.265 eV/particle 7.430 eV/particle 7.600 eV/particle 7.950 eV/particle 8.120 eV/particle 8.310 eV/particle 8.480 eV/particle 8.970 eV/particle 9.120 eV/particle 9.290 eV/particle 9.440 eV/particle 10.480 eV/particle 10.660 eV/particle 11.030 eV/particle 11.200 eV/particle 23.480 eV/particle 23.890 eV/particle 24.340 eV/particle 24.760 eV/particle 28.610 eV/particle 29.160 eV/particle 29.850 eV/particle 30.293 eV/particle 119.939 eV/particle 122.062,9 eV/particle

enthalpy of vaporization	292,9 kJ/mol
enthalpy of fusion	10,5 kJ/mol
standard enthalpy of formation	406 kJ/mol
Elektron

electron shell	2, 8, 18, 32, 18, 9, 2

valence electron	2 ⓘ

electron configuration	[Rn] 6d¹ 7s²ⓘ 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 6d¹ 7s²

oxidation number	2, 3
electronegativity	0.10033 1.1
Electrophilicity Index	0,8159546412794374 eV/particle
fundamental state of matter

phase of matter
gaseous state of matter
Boiling Point	3.473,15 K
Melting Point	1.323,15 K
critical pressure
critical temperature
triple point
appearance
litur	Black #ffffff #70abfa #70abfa
appearance
refractive index
thermodynamic material property
Thermal Conductivity
thermal expansion
molar heat capacity	27,2 J/(mol K)
Specific Heat Capacity	0,12 J/(g⋅K)
heat capacity ratio
electrical properties
type
electrical conductivity
electrical resistivity
superconductivity
magnetism
type
magnetic susceptibility (Mass)
magnetic susceptibility (Molar)
magnetic susceptibility (Volume)
magnetic ordering
Curie temperature
Néel temperature
bygnaður
Crystal Structure	{ERROR}
lattice constant	5,31 Å
Lattice Angles	π/2, π/2, π/2
mechanical property
hardness
bulk modulus
shear modulus
Young's modulus
Poisson's ratio
speed of sound
classification
Category	Actinides, Actinides
CAS Group	IIIA
IUPAC Group	IIIB
Glawe Number	33
Mendeleev Number	14
Pettifor Number	48
Geochemical Class	U/Th decay series
Goldschmidt classification	synthetic

other

Gas Basicity
polarizability	203 ± 12 a₀
C6 Dispersion Coefficient
allotrope
Neutron cross section	880
Neutron Mass Absorption	0,078
quantum number	2D3/2
space group	225 (Fm_3m)

Isotopes of Actinium

Stable Isotopes	0
Unstable Isotopes	33
Natural Isotopes	0

²⁰⁵Ac

mass number	205
neutron number	116
Relative Atomic Mass	205,015144152 ± 0,000063682 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	80 ± 60 ms
spin	9/2
nuclear quadrupole moment
time of discovery or invention	2014
parity	-

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

²⁰⁶Ac

mass number	206
neutron number	117
Relative Atomic Mass	206,014476477 ± 0,000069874 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	25 ± 7 ms
spin	3
nuclear quadrupole moment
time of discovery or invention	1998
parity	+

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

²⁰⁷Ac

mass number	207
neutron number	118
Relative Atomic Mass	207,011965967 ± 0,000060384 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	31 ± 8 ms
spin	9/2
nuclear quadrupole moment
time of discovery or invention	1994
parity	-

decay mode	intensity
α (α emission)	100%

²⁰⁸Ac

mass number	208
neutron number	119
Relative Atomic Mass	208,011552251 ± 0,000069225 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	97 ± 15 ms
spin	3
nuclear quadrupole moment
time of discovery or invention	1994
parity	+

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

²⁰⁹Ac

mass number	209
neutron number	120
Relative Atomic Mass	209,009495375 ± 0,000059953 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	94 ± 10 ms
spin	9/2
nuclear quadrupole moment
time of discovery or invention	1968
parity	-

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

²¹⁰Ac

mass number	210
neutron number	121
Relative Atomic Mass	210,009408625 ± 0,000066782 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	350 ± 40 ms
spin	7
nuclear quadrupole moment
time of discovery or invention	1968
parity	+

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

²¹¹Ac

mass number	211
neutron number	122
Relative Atomic Mass	211,007668846 ± 0,000057706 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	213 ± 25 ms
spin	9/2
nuclear quadrupole moment
time of discovery or invention	1968
parity	-

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

²¹²Ac

mass number	212
neutron number	123
Relative Atomic Mass	212,007836442 ± 0,000023492 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	895 ± 28 ms
spin	7
nuclear quadrupole moment
time of discovery or invention	1968
parity	+

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

²¹³Ac

mass number	213
neutron number	124
Relative Atomic Mass	213,006592665 ± 0,000012522 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	738 ± 16 ms
spin	9/2
nuclear quadrupole moment
time of discovery or invention	1968
parity	-

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

²¹⁴Ac

mass number	214
neutron number	125
Relative Atomic Mass	214,0069064 ± 0,000014547 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	8,2 ± 0,2 s
spin	5
nuclear quadrupole moment
time of discovery or invention	1968
parity	+

decay mode	intensity
α (α emission)	93%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	7%

²¹⁵Ac

mass number	215
neutron number	126
Relative Atomic Mass	215,006474061 ± 0,000013318 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	171 ± 10 ms
spin	9/2
nuclear quadrupole moment
time of discovery or invention	1968
parity	-

decay mode	intensity
α (α emission)	100%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	0.09%

²¹⁶Ac

mass number	216
neutron number	127
Relative Atomic Mass	216,008749101 ± 0,000009908 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	440 ± 16 us
spin	1
nuclear quadrupole moment
time of discovery or invention	1967
parity	-

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

²¹⁷Ac

mass number	217
neutron number	128
Relative Atomic Mass	217,009342325 ± 0,000012048 Da
g-factor	0,85111111111111 ± 0,011111111111111
natural abundance
radioactivity	☢️ radioactive element
half-life	69 ± 4 ns
spin	9/2
nuclear quadrupole moment
time of discovery or invention	1972
parity	-

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

²¹⁸Ac

mass number	218
neutron number	129
Relative Atomic Mass	218,01164886 ± 0,000061853 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	1 ± 0,04 us
spin	1
nuclear quadrupole moment
time of discovery or invention	1970
parity	-

decay mode	intensity
α (α emission)	100%

²¹⁹Ac

mass number	219
neutron number	130
Relative Atomic Mass	219,012420425 ± 0,000055263 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	9,4 ± 1 us
spin	9/2
nuclear quadrupole moment
time of discovery or invention	1970
parity	-

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

²²⁰Ac

mass number	220
neutron number	131
Relative Atomic Mass	220,014754527 ± 0,000006579 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	26,36 ± 0,19 ms
spin	3
nuclear quadrupole moment
time of discovery or invention	1970
parity	-

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

²²¹Ac

mass number	221
neutron number	132
Relative Atomic Mass	221,015599721 ± 0,000061086 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	52 ± 2 ms
spin	9/2
nuclear quadrupole moment
time of discovery or invention	1968
parity	-

decay mode	intensity
α (α emission)	100%

²²²Ac

mass number	222
neutron number	133
Relative Atomic Mass	222,017844232 ± 0,000005044 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	5 ± 0,5 s
spin	1
nuclear quadrupole moment
time of discovery or invention	1949
parity	-

decay mode	intensity
α (α emission)	99%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	1%

²²³Ac

mass number	223
neutron number	134
Relative Atomic Mass	223,019135982 ± 0,000007457 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	2,1 ± 0,05 m
spin	5/2
nuclear quadrupole moment
time of discovery or invention	1948
parity	-

decay mode	intensity
α (α emission)	99%
ϵ (electron capture)

²²⁴Ac

mass number	224
neutron number	135
Relative Atomic Mass	224,021722249 ± 0,000004389 Da
g-factor	0
natural abundance
radioactivity	☢️ radioactive element
half-life	2,78 ± 0,16 h
spin	0
nuclear quadrupole moment	0
time of discovery or invention	1948
parity	-

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	90.5%
α (α emission)	9.5%
β⁻ (β⁻ decay)

²²⁵Ac

mass number	225
neutron number	136
Relative Atomic Mass	225,023228601 ± 0,000005107 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	9,919 ± 0,0021 d
spin	3/2
nuclear quadrupole moment
time of discovery or invention	1947
parity	-

decay mode	intensity
α (α emission)	100%
14C	5.3%

²²⁶Ac

mass number	226
neutron number	137
Relative Atomic Mass	226,026096999 ± 0,000003327 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	29,37 ± 0,12 h
spin	1
nuclear quadrupole moment
time of discovery or invention	1950
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	83%
ϵ (electron capture)	17%
α (α emission)	0.006%

²²⁷Ac

mass number	227
neutron number	138
Relative Atomic Mass	227,027750594 ± 0,000002068 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	21,772 ± 0,003 y
spin	3/2
nuclear quadrupole moment
time of discovery or invention	1851
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	98.62%
α (α emission)	1.38%

²²⁸Ac

mass number	228
neutron number	139
Relative Atomic Mass	228,031019685 ± 0,000002247 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	6,15 ± 0,02 h
spin	3
nuclear quadrupole moment
time of discovery or invention	1908
parity	+

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

²²⁹Ac

mass number	229
neutron number	140
Relative Atomic Mass	229,032947 ± 0,000013 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	62,7 ± 0,5 m
spin	3/2
nuclear quadrupole moment
time of discovery or invention	1952
parity	+

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

²³⁰Ac

mass number	230
neutron number	141
Relative Atomic Mass	230,036327 ± 0,000017 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	122 ± 3 s
spin	1
nuclear quadrupole moment
time of discovery or invention	1973
parity	+

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ SF (β⁻-delayed fission)	1.2%

²³¹Ac

mass number	231
neutron number	142
Relative Atomic Mass	231,038393 ± 0,000014 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	7,5 ± 0,1 m
spin	1/2
nuclear quadrupole moment	0
time of discovery or invention	1973
parity	+

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

²³²Ac

mass number	232
neutron number	143
Relative Atomic Mass	232,042034 ± 0,000014 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	1,98 ± 0,08 m
spin	1
nuclear quadrupole moment
time of discovery or invention	1986
parity	+

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

²³³Ac

mass number	233
neutron number	144
Relative Atomic Mass	233,044346 ± 0,000014 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	143 ± 10 s
spin	1/2
nuclear quadrupole moment	0
time of discovery or invention	1983
parity	+

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

²³⁴Ac

mass number	234
neutron number	145
Relative Atomic Mass	234,048139 ± 0,000015 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	45 ± 2 s
spin	1
nuclear quadrupole moment
time of discovery or invention	1986
parity	+

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

²³⁵Ac

mass number	235
neutron number	146
Relative Atomic Mass	235,05084 ± 0,000015 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	62 ± 4 s
spin	1/2
nuclear quadrupole moment	0
time of discovery or invention	2006
parity	+

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

²³⁶Ac

mass number	236
neutron number	147
Relative Atomic Mass	236,054988 ± 0,000041 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	4,5 ± 3,6 m
spin	3
nuclear quadrupole moment
time of discovery or invention	2010
parity	+

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

²³⁷Ac

mass number	237
neutron number	148
Relative Atomic Mass	237,057993 ± 0,000429 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life
spin	1/2
nuclear quadrupole moment	0
time of discovery or invention
parity	+

decay mode	intensity
β⁻ (β⁻ decay)

søga

discoverer or inventor	André Debierne
location of discovery	France
time of discovery or invention	1899
etymology	Greek: akis, aktinos (ray).
pronunciation	ak-TIN-i-em (enskt)

source

Abundance
Abundance in Earth's crust	0,00000000055 mg/kg
natural abundance (hav)
natural abundance (human body)	0 %
natural abundance (meteoroid)
natural abundance (Sólin)	0 %
Abundance in Universe	0 %

Nuclear Screening Constants

Actinium on ChemicalAid

actinium

Actinium (Ac)

Physical Property

Chemical Property

other

Isotopes of Actinium

205Ac

206Ac

207Ac

208Ac

209Ac

210Ac

211Ac

212Ac

213Ac

214Ac

215Ac

216Ac

217Ac

218Ac

219Ac

220Ac

221Ac

222Ac

223Ac

224Ac

225Ac

226Ac

227Ac

228Ac

229Ac

230Ac

231Ac

232Ac

233Ac

234Ac

235Ac

236Ac

237Ac

søga

source

Nuclear Screening Constants

²⁰⁵Ac

²⁰⁶Ac

²⁰⁷Ac

²⁰⁸Ac

²⁰⁹Ac

²¹⁰Ac

²¹¹Ac

²¹²Ac

²¹³Ac

²¹⁴Ac

²¹⁵Ac

²¹⁶Ac

²¹⁷Ac

²¹⁸Ac

²¹⁹Ac

²²⁰Ac

²²¹Ac

²²²Ac

²²³Ac

²²⁴Ac

²²⁵Ac

²²⁶Ac

²²⁷Ac

²²⁸Ac

²²⁹Ac

²³⁰Ac

²³¹Ac

²³²Ac

²³³Ac

²³⁴Ac

²³⁵Ac

²³⁶Ac

²³⁷Ac