Pm - Promethium
Promethium Element Information, Facts, Properties, Trends, Uses, Comparison with other elements
Promethium, originally prometheum, is a chemical element with the symbol Pm and atomic number 61. All of its isotopes are radioactive; it is one of only two such elements that are followed in the periodic table by elements with stable forms, a distinction shared with technetium. Chemically, promethium is a Lanthanide, which forms salts when combined with other elements.
It belongs to group null of the periodic table having trivial name . You can also download Printable Periodic Table of Elements Flashcards for Promethium in a PDF format.
Promethium Facts
Read key information and facts about element Promethium
Name | Promethium |
Atomic Number | 61 |
Atomic Symbol | Pm |
Atomic Weight | 145 |
Phase | Solid |
Color | Silver |
Appearance | metallic |
Classification | Lanthanide |
Natural Occurance | From decay |
Group in Periodic Table | - |
Group Name | |
Period in Periodic Table | period 6 |
Block in Periodic Table | f-block |
Electronic Configuration | [Xe] 4f5 6s2 |
Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 23, 8, 2 |
Melting Point | 1373 K |
Boiling Point | 3273 K |
CAS Number | CAS7440-12-2 |
How to Locate Promethium 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 61 to find Promethium 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 Promethium on periodic table look for cross section of group - and period 6 in the modern periodic table.
Promethium History
The element Promethium was discovered by S. Wu,E.G. Segrè and H. Bethe in year 1942 in United States. Promethium was first isolated by Charles D. Coryell,Jacob A. Marinsky,Lawrence E. Glendenin, and Harold G. Richter in 1945. Promethium derived its name from Prometheus of Greek mythology who stole fire from the Gods and gave it to humans.
Discovered By | S. Wu,E.G. Segrè and H. Bethe |
Discovery Date | 1942 in United States |
First Isolation | 1945 |
Isolated by | Charles D. Coryell,Jacob A. Marinsky,Lawrence E. Glendenin, and Harold G. Richter |
It was probably first prepared in 1942 by bombarding neodymium and praseodymium with neutrons, but separation of the element could not be carried out. Isolation was performed under the Manhattan Project in 1945.
Promethium Uses
Promethium is used majorly for research in radiation. It can be used in nuclear batteries and as a light source for signals. Researchers believe that it could soon be used in portable x-ray machines.
Promethium Presence: Abundance in Nature and Around Us
The table below shows the abundance of Promethium 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 | - | 0.005 |
Abundance in Meteorites | - | - |
Abundance in Earth's Crust | - | - |
Abundance in Oceans | - | - |
Abundance in Humans | - | - |
Crystal Structure of Promethium
The solid state structure of Promethium is Simple Hexagonal.
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 |
---|---|---|
and the angles between them Lattice Angles (alpha, beta and gamma).
alpha | beta | gamma |
---|---|---|
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 | - |
Space Group Number | - |
Crystal Structure | Simple Hexagonal |
Number of atoms per unit cell |
The number of atoms per unit cell in a simple cubic, face-centered cubic and body-centred cubic are 1,4,2 respectively.
Promethium Atomic and Orbital Properties
Promethium atoms have 61 electrons and the electronic shell structure is [2, 8, 18, 23, 8, 2] with Atomic Term Symbol (Quantum Numbers) 6H5/2.
Atomic Number | 61 |
Number of Electrons (with no charge) | 61 |
Number of Protons | 61 |
Mass Number | 145 |
Number of Neutrons | 84 |
Shell structure (Electrons per energy level) | 2, 8, 18, 23, 8, 2 |
Electron Configuration | [Xe] 4f5 6s2 |
Valence Electrons | 4f5 6s2 |
Valence (Valency) | 3 |
Main Oxidation States | 3 |
Oxidation States | 2, 3 |
Atomic Term Symbol (Quantum Numbers) | 6H5/2 |
Bohr Atomic Model of Promethium - Electrons per energy level
n | s | p | d | f |
---|
Ground State Electronic Configuration of Promethium - neutral Promethium atom
Abbreviated electronic configuration of Promethium
The ground state abbreviated electronic configuration of Neutral Promethium atom is [Xe] 4f5 6s2. The portion of Promethium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Xe]. 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 4f5 6s2, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Promethium
Complete ground state electronic configuration for the Promethium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f5 6s2
Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.
As per the Aufbau principle the electrons will occupy the orbitals having lower energies before occupying higher energy orbitals. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
The Pauli exclusion principle states that a maximum of two electrons, each having opposite spins, can fit in an orbital.
Hund's rule states that every orbital in a given subshell is singly occupied by electrons before a second electron is filled in an orbital.
Atomic Structure of Promethium
Promethium atomic radius is 205 pm, while it's covalent radius is -.
Atomic Radius Calculated | 205 pm(2.05 Å) |
Atomic Radius Empirical | 185 pm (1.85 Å) |
Atomic Volume | 20.23 cm3/mol |
Covalent Radius | - |
Van der Waals Radius | - |
Neutron Cross Section | 8000 |
Neutron Mass Absorption | - |
Spectral Lines of Promethium - Atomic Spectrum of Promethium
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identify atoms and molecules.
Spectral lines are the result of interaction between a quantum system and a single photon. A spectral line may be observed either as an emission line or an absorption line.
Spectral lines are highly atom-specific, and can be used to identify the chemical composition of any medium. Several elements, including helium, thallium, and caesium, were discovered by spectroscopic means. They are widely used to determine the physical conditions of stars and other celestial bodies that cannot be analyzed by other means.
Emission spectrum of Promethium
Absorption spectrum of Promethium
Promethium Chemical Properties: Promethium Ionization Energies and electron affinity
The electron affinity of Promethium is 50 kJ/mol.
Valence | 3 |
Electronegativity | 1.13 |
ElectronAffinity | 50 kJ/mol |
Ionization Energy of Promethium
Ionization energy is the amount of energy required to remove an electron from an atom or molecule.in chemistry, this energy is expresed in kilocalories per mole (kcal/mol) or kilojoules per mole (kJ/mol).
Refer to table below for Ionization energies of Promethium
Ionization energy number | Enthalpy - kJ/mol |
---|---|
1st | 540 |
2nd | 1050 |
3rd | 2150 |
4th | 3970 |
Promethium Physical Properties
Refer to below table for Promethium Physical Properties
Density | 7.264 g/cm3 |
Molar Volume | 20.23 cm3/mol |
Elastic Properties
Young Modulus | 46 |
Shear Modulus | 18 GPa |
Bulk Modulus | 33 GPa |
Poisson Ratio | 0.28 |
Hardness of Promethium - Tests to Measure of Hardness of Element
Mohs Hardness | - |
Vickers Hardness | - |
Brinell Hardness | - |
Promethium Electrical Properties
Electrical resistivity measures element's electrical resistance or how strongly it resists electric current.The SI unit of electrical resistivity is the ohm-metre (Ω⋅m). While Electrical conductivity is the reciprocal of electrical resistivity. It represents a element's ability to conduct electric current. The SI unit of electrical conductivity is siemens per metre (S/m).
Promethium is a conductor of electricity. Refer to table below for the Electrical properties of Promethium
Electrical conductors | Conductor |
Electrical Conductivity | 1300000 S/m |
Resistivity | 7.5e-7 m Ω |
Superconducting Point | - |
Promethium Heat and Conduction Properties
Thermal Conductivity | 15 W/(m K) |
Thermal Expansion | 0.000011 /K |
Promethium Magnetic Properties
Magnetic Type | - |
Curie Point | - |
Mass Magnetic Susceptibility | - |
Molar Magnetic Susceptibility | - |
Volume Magnetic Susceptibility | - |
Optical Properties of Promethium
Refractive Index | - |
Acoustic Properties of Promethium
Speed of Sound | - |
Promethium Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Promethium
Melting Point | 1373 K(1099.85 °C, 2011.730 °F) |
Boiling Point | 3273 K(2999.85 °C, 5431.730 °F) |
Critical Temperature | - |
Superconducting Point | - |
Enthalpies of Promethium
Heat of Fusion | 7.7 kJ/mol |
Heat of Vaporization | 290 kJ/mol |
Heat of Combustion | - |
Promethium Isotopes - Nuclear Properties of Promethium
Promethium has 38 isotopes, with between 126 and 163 nucleons. Promethium has 1 stable naturally occuring isotopes.
Isotopes of Promethium - Naturally occurring stable Isotopes: None.
Isotope | Z | N | Isotope Mass | % Abundance | T half | Decay Mode |
---|---|---|---|---|---|---|
126Pm | 61 | 65 | 126 | Synthetic | ||
127Pm | 61 | 66 | 127 | Synthetic | ||
128Pm | 61 | 67 | 128 | Synthetic | ||
129Pm | 61 | 68 | 129 | Synthetic | ||
130Pm | 61 | 69 | 130 | Synthetic | ||
131Pm | 61 | 70 | 131 | Synthetic | ||
132Pm | 61 | 71 | 132 | Synthetic | ||
133Pm | 61 | 72 | 133 | Synthetic | ||
134Pm | 61 | 73 | 134 | Synthetic | ||
135Pm | 61 | 74 | 135 | Synthetic | ||
136Pm | 61 | 75 | 136 | Synthetic | ||
137Pm | 61 | 76 | 137 | Synthetic | ||
138Pm | 61 | 77 | 138 | Synthetic | ||
139Pm | 61 | 78 | 139 | Synthetic | ||
140Pm | 61 | 79 | 140 | Synthetic | ||
141Pm | 61 | 80 | 141 | Synthetic | ||
142Pm | 61 | 81 | 142 | Synthetic | ||
143Pm | 61 | 82 | 143 | Synthetic | ||
144Pm | 61 | 83 | 144 | Synthetic | ||
145Pm | 61 | 84 | 145 | Synthetic | 17.73 years | ElectronCapture |
146Pm | 61 | 85 | 146 | Synthetic | ||
147Pm | 61 | 86 | 147 | Synthetic | ||
148Pm | 61 | 87 | 148 | Synthetic | ||
149Pm | 61 | 88 | 149 | Synthetic | ||
150Pm | 61 | 89 | 150 | Synthetic | ||
151Pm | 61 | 90 | 151 | Synthetic | ||
152Pm | 61 | 91 | 152 | Synthetic | ||
153Pm | 61 | 92 | 153 | Synthetic | ||
154Pm | 61 | 93 | 154 | Synthetic | ||
155Pm | 61 | 94 | 155 | Synthetic | ||
156Pm | 61 | 95 | 156 | Synthetic | ||
157Pm | 61 | 96 | 157 | Synthetic | ||
158Pm | 61 | 97 | 158 | Synthetic | ||
159Pm | 61 | 98 | 159 | Synthetic | ||
160Pm | 61 | 99 | 160 | Synthetic | ||
161Pm | 61 | 100 | 161 | Synthetic | ||
162Pm | 61 | 101 | 162 | Synthetic | ||
163Pm | 61 | 102 | 163 | Synthetic |
Regulatory and Health - Health and Safety Parameters and Guidelines
The United States Department of Transportation (DOT) identifies hazard class of all dangerous elements/goods/commodities either by its class (or division) number or name. The DOT has divided these materials into nine different categories, known as Hazard Classes.
NFPA 704 is a Standard System for the Identification of the Hazards of Materials for Emergency Response. NFPA is a standard maintained by the US based National Fire Protection Association.
The health (blue), flammability (red), and reactivity (yellow) rating all use a numbering scale ranging from 0 to 4. A value of zero means that the element poses no hazard; a rating of four indicates extreme danger.
NFPA Fire Rating | N/A | N/A |
NFPA Health Rating | N/A | N/A |
NFPA Reactivity Rating | N/A | N/A |
NFPA Hazards | N/A |
Autoignition Point | - |
Flashpoint | - |
Database Search
List of unique identifiers to search the element in various chemical registry databases
Database | Identifier number |
---|---|
CAS Number - Chemical Abstracts Service (CAS) | CAS7440-12-2 |
RTECS Number | - |
CID Number | - |
Gmelin Number | - |
NSC Number | - |
Compare Promethium with other elements
Compare Promethium with Group , Period 6 and Lanthanide elements of the periodic table.
Compare Promethium with all Group elements
Compare Promethium with all Period 6 elements
Compare Promethium with all Lanthanide elements
Frequently Asked Questions (FAQ)
Find the answers to the most frequently asked questions about Promethium