Ac Actinium
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements
Actinium is a radioactive chemical element with symbol Ac (not to be confused with the abbreviation for an acetyl group) and atomic number 89, which was discovered in 1899. It was the first non-primordial radioactive element to be isolated. Polonium, radium and radon were observed before actinium, but they were not isolated until 1902.
It belongs to group of the periodic table having trivial name .
Actinium Facts
Read key information and facts about element Actinium
| Name | Actinium |
| Atomic Number | 89 |
| Atomic Symbol | Ac |
| Atomic Weight | 227 |
| Phase | Solid |
| Color | Silver |
| Appearance | - |
| Classification | Actinide |
| Group in Periodic Table | - |
| Group Name | |
| Period in Periodic Table | period 7 |
| Block in Periodic Table | f -block |
| Electronic Configuration | [Rn] 6d1 7s2 |
| Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 32, 18, 9, 2 |
| Melting Point | 1323 K |
| Boiling Point | 3473 K |
| CAS Number | CAS7440-34-8 |
How to Locate Actinium on Periodic Table
Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 89 to find Actinium on periodic table.
Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Actinium on periodic table look for cross section of group - and period 7 in the modern periodic table.
Actinium History
The element Actinium was discovered by F. O. Giesel in year 1902 in France. Actinium was first isolated by F. O. Giesel in 1902. Actinium derived its name from the Greek aktis, 'ray'.
Giesel obtained from pitchblende a substance that had properties similar to those of lanthanum and named itemanium. André-Louis Debiernehad previously reported the discovery of a new element actinium that was supposedly similar to titanium and thorium; the elements were mistakenly identified as being identical and Debierne's name was chosen, even though in retrospect Debierne's substance could not have included much actual element 89.
Actinium Presence: Abundance in Nature and Around Us
The table below shows the abundance of Actinium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
| ppb by weight (1ppb =10^-7 %) | ppb by atoms (1ppb =10^-7 %) | |
|---|---|---|
| Abundance in Universe | - | - |
| Abundance in Sun | - | - |
| Abundance in Meteorites | - | - |
| Abundance in Earth's Crust | - | - |
| Abundance in Oceans | - | - |
| Abundance in Humans | - | - |
Crystal Structure of Actinium
The solid state structure of Actinium is Face Centered Cubic.
The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.
Unit Cell Parameters
The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)
| a | b | c |
|---|---|---|
| 567 pm | 567 pm | 567 pm |
and the angles between them Lattice Angles (alpha, beta and gamma).
| alpha | beta | gamma |
|---|---|---|
| π/2 | π/2 | π/2 |
The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.
The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.
| Space Group Name | Fm_ 3m |
| Space Group Number | 225 |
| Crystal Structure | Face Centered Cubic |
| Number of atoms per unit cell | 4 |
The number of atoms per unit cell in a simple cubic, face-centered cubic and body-centred cubic are 1,4,2 respectively.
Actinium Atomic and Orbital Properties
Actinium atoms have 89 electrons and the electronic shell structure is [2, 8, 18, 32, 18, 9, 2] with Atomic Term Symbol (Quantum Numbers) 2D3/2.
| Atomic Number | 89 |
| Number of Electrons (with no charge) | 89 |
| Number of Protons | 89 |
| Mass Number | 227 |
| Number of Neutrons | 138 |
| Shell structure (Electrons per energy level) | 2, 8, 18, 32, 18, 9, 2 |
| Electron Configuration | [Rn] 6d1 7s2 |
| Valence Electrons | 6d1 7s2 |
| Valence (Valency) | 3 |
| Main Oxidation States | 3 |
| Oxidation States | 2, 3 |
| Atomic Term Symbol (Quantum Numbers) | 2D3/2 |
Bohr Atomic Model of Actinium - Electrons per energy level
| n | s | p | d | f |
|---|
Ground State Electronic Configuration of Actinium - neutral Actinium atom
Abbreviated electronic configuration of Actinium
The ground state abbreviated electronic configuration of Neutral Actinium atom is [Rn] 6d1 7s2. The portion of Actinium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Rn]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 6d1 7s2, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Actinium
Complete ground state electronic configuration for the Actinium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6 6d1 7s2
Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.
Atomic Structure of Actinium
Actinium atomic radius is 195 pm, while it's covalent radius is - .
| Atomic Radius Calculated | 195 pm (1.95 Å) |
| Atomic Radius Empirical | 195 pm (1.95 Å) |
| Atomic Volume | 22.5422 cm3/mol |
| Covalent Radius | - |
| Van der Waals Radius | - |
| Neutron Cross Section | 810 |
| Neutron Mass Absorption | 0.079 |
Atomic Spectrum of Actinium
Actinium Chemical Properties: Actinium Ionization Energies and electron affinity
The electron affinity of Actinium is - .
| Valence | 3 |
| Electronegativity | 1.1 |
| ElectronAffinity | - |
Ionization Energy of Actinium
Refer to table below for Ionization energies of Actinium
| Ionization energy number | Enthalpy - kJ/mol |
|---|---|
| 1st | 499 |
| 2nd | 1170 |
Actinium Physical Properties
Refer to below table for Actinium Physical Properties
| Density | 10.07 g/cm3 |
| Molar Volume | 22.5422 cm3/mol |
Elastic Properties
| Young Modulus | - |
| Shear Modulus | - |
| Bulk Modulus | - |
| Poisson Ratio | - |
Hardness of Actinium - Tests to Measure of Hardness of Element
| Mohs Hardness | - |
| Vickers Hardness | - |
| Brinell Hardness | - |
Actinium Electrical Properties
Actinium is Conductor of electricity. Refer to table below for the Electrical properties ofActinium
| Electrical Conductivity | - |
| Resistivity | - |
| Superconducting Point | - |
Actinium Heat and Conduction Properties
| Thermal Conductivity | 12 W/(m K) |
| Thermal Expansion | - |
Actinium Magnetic Properties
| Magnetic Type | - |
| Curie Point | - |
| Mass Magnetic Susceptibility | - |
| Molar Magnetic Susceptibility | - |
| Volume Magnetic Susceptibility | - |
Optical Properties of Actinium
| Refractive Index | - |
Acoustic Properties of Actinium
| Speed of Sound | - |
Actinium Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Actinium
| Melting Point | 1323 K (1049.85°C, 1921.73 °F) |
| Boiling Point | 3473 K (3199.85°C, 5791.73 °F) |
| Critical Temperature | - |
| Superconducting Point | - |
Enthalpies of Actinium
| Heat of Fusion | 14 kJ/mol |
| Heat of Vaporization | 400 kJ/mol |
| Heat of Combustion | - |
Actinium Isotopes - Nuclear Properties of Actinium
Actinium has 31 isotopes, with between 206 and 236 nucleons. Actinium has 0 stable naturally occuring isotopes.
Isotopes of Actinium - Naturally occurring stable Isotopes: -.
| Isotope | Z | N | Isotope Mass | % Abundance | T half | Decay Mode |
|---|---|---|---|---|---|---|
| 206Ac | 89 | 117 | 206 | Synthetic | ||
| 207Ac | 89 | 118 | 207 | Synthetic | ||
| 208Ac | 89 | 119 | 208 | Synthetic | ||
| 209Ac | 89 | 120 | 209 | Synthetic | ||
| 210Ac | 89 | 121 | 210 | Synthetic | ||
| 211Ac | 89 | 122 | 211 | Synthetic | ||
| 212Ac | 89 | 123 | 212 | Synthetic | ||
| 213Ac | 89 | 124 | 213 | Synthetic | ||
| 214Ac | 89 | 125 | 214 | Synthetic | ||
| 215Ac | 89 | 126 | 215 | Synthetic | ||
| 216Ac | 89 | 127 | 216 | Synthetic | ||
| 217Ac | 89 | 128 | 217 | Synthetic | ||
| 218Ac | 89 | 129 | 218 | Synthetic | ||
| 219Ac | 89 | 130 | 219 | Synthetic | ||
| 220Ac | 89 | 131 | 220 | Synthetic | ||
| 221Ac | 89 | 132 | 221 | Synthetic | ||
| 222Ac | 89 | 133 | 222 | Synthetic | ||
| 223Ac | 89 | 134 | 223 | Synthetic | ||
| 224Ac | 89 | 135 | 224 | Synthetic | ||
| 225Ac | 89 | 136 | 225 | Synthetic | ||
| 226Ac | 89 | 137 | 226 | Synthetic | ||
| 227Ac | 89 | 138 | 227 | Synthetic | 21.7865 years | BetaDecay |
| 228Ac | 89 | 139 | 228 | Synthetic | ||
| 229Ac | 89 | 140 | 229 | Synthetic | ||
| 230Ac | 89 | 141 | 230 | Synthetic | ||
| 231Ac | 89 | 142 | 231 | Synthetic | ||
| 232Ac | 89 | 143 | 232 | Synthetic | ||
| 233Ac | 89 | 144 | 233 | Synthetic | ||
| 234Ac | 89 | 145 | 234 | Synthetic | ||
| 235Ac | 89 | 146 | 235 | Synthetic | ||
| 236Ac | 89 | 147 | 236 | Synthetic |
Regulatory and Health - Health and Safety Parameters and Guidelines
Database Search
List of unique identifiers to search the element in various chemical registry databases
| Database | Identifier number |
|---|---|
| CAS Number - Chemical Abstracts Service (CAS) | CAS7440-34-8 |
| RTECS Number | - |
| CID Number | - |
| Gmelin Number | - |
| NSC Number | - |
Compare Actinium with other elements
Compare Actinium with all Group elements
Compare Actinium with all Period 7 elements
Compare Actinium with all Actinide elements
FAQs
What is the electronic configuration of Actinium?
The electronic configuration of Actinium is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6 6d1 7s2.
What is the abbreviated electronic configuration of Actinium?
The abbreviated electronic configuration of Actinium is [Rn] 6d1 7s2. To form abbreviated notation of electronic configuration, the completely filled subshells are replaced by the noble gas of the preceding period in square brackets.
What is the symbol of Actinium?
Symbol of Actinium is Ac. Actinium is a chemical element with symbol Ac and atomic number 89.
What is the position of Actinium in the Periodic Table?
Actinium is a chemical element with the symbol Ac and atomic number 89. Actinium is the 89 element on the periodic table. It is located in group null and period 7 in the modern periodic table.
What is the atomic number of Actinium?
The atomic number of Actinium is 89.
What is the color of Actinium?
Actinium is of Silver color.
Who discovered Actinium?
The element Actinium was discovered by F. O. Giesel in year 1902 in France. Actinium was first isolated by F. O. Giesel in 1902.
How many valence electrons does a Actinium atom have?
Actinium has 3 valence electrons. Actinium has 89 electrons out of which 3 valence electrons are present in the 6d1 7s2 outer orbitals of atom.
What is the melting Point of Actinium?
Melting Point of Actinium is 1323 K.
What is the boiling Point of Actinium?
Boiling Point of Actinium is 3473 K.
What is the melting Point of Actinium in Kelvin?
Melting Point of Actinium in Kelvin is 1323 K.
What is the boiling Point of Actinium in Kelvin?
Boiling Point of Actinium in Kelvin is 3473 K.
What is the electronic configuration of Actinium 89?
The electronic configuration of Actinium will be 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6 6d1 7s2.
How do you write the electron configuration for Actinium?
The electronic configuration of Actinium will be 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6 6d1 7s2.