Elements
89

Ac

Actinium

Actinium (Ac) is a silvery colored radioactive metal that has the atomic number 89 in the periodic table. It is an Actinoid Metal with the symbol Ac.

Actinium was first isolated in 1899 by French chemist André-Louis Debierne, a French scientist. Actinium is a soft radioactive metal that reacts with oxygen to form a layer of actinium oxide. It is not found naturally in the earths crust but exists in ores of uranium and thorium. It emits beta and alpha particles. It does not have many uses due to its rarity but it is used in nuclear generators of spacecraft with other elements as a neutron source. It has been researched for its use in radiotherapy due to its short half life and beta production. It is a solid metal at room temperature and it has a melting point of 1227°c and a boiling point of 3200°c.

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FAQ's

What is the Melting Point for Actinium?

Actinium has a Melting Point of 1050°F, meaning at 1050°F it will turn to a liquid.

What is the Boiling Point for Actinium?

Actinium has a Boiling Point of 3200°F, meaning at 3200°F it will turn to a Gas.

What is the Electronegativity of Actinium?

Actinium's Electronegativty is 1.1. Electronegativity is a measure of how strongly atoms attract bonding electrons to themselves.

What is the Heat of Vaporization of Actinium?

Actinium has a Heat of Vaporization of kJ/mol.

Uses

It has no significant commercial applications.

Sources

Extremely rare, found in all uranium ores. Usually obtained by treating radium with neutrons in a reactor.

89
Protons
89
Electrons
138
Neutrons

Ac

Element Symbol
Ac
Atomic Weight
227
Atomic Number
89
State
Solid
Melting Point
Unknown
1050
°C
Boiling Point
3200
Unknown
°C
Heat of Vaporization
Unknown
kJ/mol
Crystal Structure
Cubic: Face centered
Thermoconductivity
0.12
Unknown
W/cmK
Shells
2,8,18,32,18,9,2
Group
Actinide
Period
7
Block
F Block
Orbitals
[Rn] 6d1 7s2
Coefficient of Thermal Expansion
--
Covalent Radius
--
Density at 293K
10.07 g/cm³
Electrical Conductivity
--
First Ionization Potential
5.17 V
Second Ionization Potential
12.126 V
Third Ionization Potential
--
Ionic Radius
--
Oxydation States
3
Lattice Parameter
5.311 Å
Lattice Parameter 2
--
Lattice Parameter 3
4.9550 Å
Pronounced

ak-TIN-i-em

Discovered by

André Debierne

Discovery date

1899

Orbital configuration
2,8,18,32,18,9,2

Download the Periodic Table

Explore Other Actinides

257
100

Fm

Fermium
258
101

Md

Mendelevium
238.029
92

U

Uranium
243
95

Am

Americium
237
93

Np

Neptunium
247
96

Cm

Curium
252
99

Es

Einsteinium
251
98

Cf

Californium
244
94

Pu

Plutonium
231.036
91

Pa

Protactinium
247
97

Bk

Berkelium
259
102

No

Nobelium
262
103

Lr

Lawrencium
232.038
90

Th

Thorium
The actinide series contains 15 metallic elements from number 89 (actinium) to 103 (lawrencium). They are located in group 3 in the periodic table.
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Radium

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Thorium

90