Pr - Praseodymium
Praseodymium Element Information, Facts, Properties, Trends, Uses, Comparison with other elements
Praseodymium is a chemical element with symbol Pr and atomic number 59. Praseodymium is a soft, silvery, malleable and ductile metal in the Lanthanide group. It is valued for its magnetic, electrical, chemical, and optical properties.
It belongs to group null of the periodic table having trivial name . You can also download Printable Periodic Table of Elements Flashcards for Praseodymium in a PDF format.
Praseodymium Facts
Read key information and facts about element Praseodymium
| Name | Praseodymium |
| Atomic Number | 59 |
| Atomic Symbol | Pr |
| Atomic Weight | 140.90765 |
| Phase | Solid |
| Color | Silver |
| Appearance | grayish white |
| Classification | Lanthanide |
| Natural Occurance | Primordial |
| Group in Periodic Table | - |
| Group Name | |
| Period in Periodic Table | period 6 |
| Block in Periodic Table | f-block |
| Electronic Configuration | [Xe] 4f3 6s2 |
| Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 21, 8, 2 |
| Melting Point | 1204 K |
| Boiling Point | 3563 K |
| CAS Number | CAS7440-10-0 |
How to Locate Praseodymium 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 59 to find Praseodymium 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 Praseodymium on periodic table look for cross section of group - and period 6 in the modern periodic table.
Praseodymium History
The element Praseodymium was discovered by C. A. von Welsbach in year 1885 in Austria. Praseodymium was first isolated by in . Praseodymium derived its name from the Greek praseios didymos meaning 'green twin'.
| Discovered By | C. A. von Welsbach |
| Discovery Date | 1885 in Austria |
| First Isolation | |
| Isolated by |
Von Welsbach discovered two new distinct elements in Mosander's didymia: praseodymium and neodymium.
Praseodymium Uses
Praseodymium is used to make yellow glass goggles for welders. Praseodymium is also used in flint lighter products. Its prime use, however, is to color glass and enamels.
Praseodymium Presence: Abundance in Nature and Around Us
The table below shows the abundance of Praseodymium 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 | 2 | 0.02 |
| Abundance in Sun | 1 | 0.005 |
| Abundance in Meteorites | 100 | 10 |
| Abundance in Earth's Crust | 8700 | 1300 |
| Abundance in Oceans | 0.0006 | 0.000026 |
| Abundance in Humans | - | - |
Crystal Structure of Praseodymium
The solid state structure of Praseodymium 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 |
|---|---|---|
| 367.25 pm | 367.25 pm | 1183.54 pm |
and the angles between them Lattice Angles (alpha, beta and gamma).
| alpha | beta | gamma |
|---|---|---|
| π/2 | π/2 | 2 π/3 |
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 | P63/mmc |
| Space Group Number | 194 |
| 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.
Praseodymium Atomic and Orbital Properties
Praseodymium atoms have 59 electrons and the electronic shell structure is [2, 8, 18, 21, 8, 2] with Atomic Term Symbol (Quantum Numbers) 4I9/2.
| Atomic Number | 59 |
| Number of Electrons (with no charge) | 59 |
| Number of Protons | 59 |
| Mass Number | 141 |
| Number of Neutrons | 82 |
| Shell structure (Electrons per energy level) | 2, 8, 18, 21, 8, 2 |
| Electron Configuration | [Xe] 4f3 6s2 |
| Valence Electrons | 4f3 6s2 |
| Valence (Valency) | 4 |
| Main Oxidation States | 3 |
| Oxidation States | 0, 1, 2, 3, 4, 5 |
| Atomic Term Symbol (Quantum Numbers) | 4I9/2 |
Bohr Atomic Model of Praseodymium - Electrons per energy level
| n | s | p | d | f |
|---|
Ground State Electronic Configuration of Praseodymium - neutral Praseodymium atom
Abbreviated electronic configuration of Praseodymium
The ground state abbreviated electronic configuration of Neutral Praseodymium atom is [Xe] 4f3 6s2. The portion of Praseodymium 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 4f3 6s2, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Praseodymium
Complete ground state electronic configuration for the Praseodymium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f3 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 Praseodymium
Praseodymium atomic radius is 247 pm, while it's covalent radius is -.
| Atomic Radius Calculated | 247 pm(2.47 Å) |
| Atomic Radius Empirical | 185 pm (1.85 Å) |
| Atomic Volume | 20.8 cm3/mol |
| Covalent Radius | - |
| Van der Waals Radius | - |
| Neutron Cross Section | 11.4 |
| Neutron Mass Absorption | 0.0029 |
Spectral Lines of Praseodymium - Atomic Spectrum of Praseodymium
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 Praseodymium
Absorption spectrum of Praseodymium
Praseodymium Chemical Properties: Praseodymium Ionization Energies and electron affinity
The electron affinity of Praseodymium is 50 kJ/mol.
| Valence | 4 |
| Electronegativity | 1.13 |
| ElectronAffinity | 50 kJ/mol |
Ionization Energy of Praseodymium
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 Praseodymium
| Ionization energy number | Enthalpy - kJ/mol |
|---|---|
| 1st | 527 |
| 2nd | 1020 |
| 3rd | 2086 |
| 4th | 3761 |
| 5th | 5551 |
Praseodymium Physical Properties
Refer to below table for Praseodymium Physical Properties
| Density | 6.64 g/cm3(when liquid at m.p density is $6.5 g/cm3) |
| Molar Volume | 20.8 cm3/mol |
Elastic Properties
| Young Modulus | 37 |
| Shear Modulus | 15 GPa |
| Bulk Modulus | 29 GPa |
| Poisson Ratio | 0.28 |
Hardness of Praseodymium - Tests to Measure of Hardness of Element
| Mohs Hardness | - |
| Vickers Hardness | 400 MPa |
| Brinell Hardness | 481 MPa |
Praseodymium 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).
Praseodymium is a conductor of electricity. Refer to table below for the Electrical properties of Praseodymium
| Electrical conductors | Conductor |
| Electrical Conductivity | 1400000 S/m |
| Resistivity | 7e-7 m Ω |
| Superconducting Point | - |
Praseodymium Heat and Conduction Properties
| Thermal Conductivity | 13 W/(m K) |
| Thermal Expansion | 0.0000067 /K |
Praseodymium Magnetic Properties
| Magnetic Type | Paramagnetic |
| Curie Point | - |
| Mass Magnetic Susceptibility | 4.23e-7 m3/kg |
| Molar Magnetic Susceptibility | 5.9604e-8 m3/mol |
| Volume Magnetic Susceptibility | 0.0028087 |
Optical Properties of Praseodymium
| Refractive Index | - |
Acoustic Properties of Praseodymium
| Speed of Sound | 2280 m/s |
Praseodymium Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Praseodymium
| Melting Point | 1204 K(930.85 °C, 1707.530 °F) |
| Boiling Point | 3563 K(3289.85 °C, 5953.730 °F) |
| Critical Temperature | - |
| Superconducting Point | - |
Enthalpies of Praseodymium
| Heat of Fusion | 6.9 kJ/mol |
| Heat of Vaporization | 330 kJ/mol |
| Heat of Combustion | - |
Praseodymium Isotopes - Nuclear Properties of Praseodymium
Praseodymium has 39 isotopes, with between 121 and 159 nucleons. Praseodymium has 1 stable naturally occuring isotopes.
Isotopes of Praseodymium - Naturally occurring stable Isotopes: 141Pr.
| Isotope | Z | N | Isotope Mass | % Abundance | T half | Decay Mode |
|---|---|---|---|---|---|---|
| 121Pr | 59 | 62 | 121 | Synthetic | ||
| 122Pr | 59 | 63 | 122 | Synthetic | ||
| 123Pr | 59 | 64 | 123 | Synthetic | ||
| 124Pr | 59 | 65 | 124 | Synthetic | ||
| 125Pr | 59 | 66 | 125 | Synthetic | ||
| 126Pr | 59 | 67 | 126 | Synthetic | ||
| 127Pr | 59 | 68 | 127 | Synthetic | ||
| 128Pr | 59 | 69 | 128 | Synthetic | ||
| 129Pr | 59 | 70 | 129 | Synthetic | ||
| 130Pr | 59 | 71 | 130 | Synthetic | ||
| 131Pr | 59 | 72 | 131 | Synthetic | ||
| 132Pr | 59 | 73 | 132 | Synthetic | ||
| 133Pr | 59 | 74 | 133 | Synthetic | ||
| 134Pr | 59 | 75 | 134 | Synthetic | ||
| 135Pr | 59 | 76 | 135 | Synthetic | ||
| 136Pr | 59 | 77 | 136 | Synthetic | ||
| 137Pr | 59 | 78 | 137 | Synthetic | ||
| 138Pr | 59 | 79 | 138 | Synthetic | ||
| 139Pr | 59 | 80 | 139 | Synthetic | ||
| 140Pr | 59 | 81 | 140 | Synthetic | ||
| 141Pr | 59 | 82 | 141 | 100% | Stable | |
| 142Pr | 59 | 83 | 142 | Synthetic | ||
| 143Pr | 59 | 84 | 143 | Synthetic | ||
| 144Pr | 59 | 85 | 144 | Synthetic | ||
| 145Pr | 59 | 86 | 145 | Synthetic | ||
| 146Pr | 59 | 87 | 146 | Synthetic | ||
| 147Pr | 59 | 88 | 147 | Synthetic | ||
| 148Pr | 59 | 89 | 148 | Synthetic | ||
| 149Pr | 59 | 90 | 149 | Synthetic | ||
| 150Pr | 59 | 91 | 150 | Synthetic | ||
| 151Pr | 59 | 92 | 151 | Synthetic | ||
| 152Pr | 59 | 93 | 152 | Synthetic | ||
| 153Pr | 59 | 94 | 153 | Synthetic | ||
| 154Pr | 59 | 95 | 154 | Synthetic | ||
| 155Pr | 59 | 96 | 155 | Synthetic | ||
| 156Pr | 59 | 97 | 156 | Synthetic | ||
| 157Pr | 59 | 98 | 157 | Synthetic | ||
| 158Pr | 59 | 99 | 158 | Synthetic | ||
| 159Pr | 59 | 100 | 159 | 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) | CAS7440-10-0 |
| RTECS Number | - |
| CID Number | CID23942 |
| Gmelin Number | - |
| NSC Number | - |
Compare Praseodymium with other elements
Compare Praseodymium with Group , Period 6 and Lanthanide elements of the periodic table.
Compare Praseodymium with all Group elements
Compare Praseodymium with all Period 6 elements
Compare Praseodymium with all Lanthanide elements
Frequently Asked Questions (FAQ)
Find the answers to the most frequently asked questions about Praseodymium