Cm - Curium
Curium Element Information, Facts, Properties, Trends, Uses, Comparison with other elements
Curium is a transuranic radioactive chemical element with symbol Cm and atomic number 96. This element of the Actinide series was named after Marie and Pierre Curie – both were known for their research on radioactivity. Curium was first intentionally produced and identified in July 1944 by the group of Glenn T. Seaborg at the University of California, Berkeley.
It belongs to group null of the periodic table having trivial name . You can also download Printable Periodic Table of Elements Flashcards for Curium in a PDF format.
Curium Facts
Read key information and facts about element Curium
Name | Curium |
Atomic Number | 96 |
Atomic Symbol | Cm |
Atomic Weight | 247 |
Phase | Solid |
Color | Silver |
Appearance | silvery metallic, glows purple in the dark |
Classification | Actinide |
Natural Occurance | Synthetic |
Group in Periodic Table | - |
Group Name | |
Period in Periodic Table | period 7 |
Block in Periodic Table | f-block |
Electronic Configuration | [Rn] 5f7 6d1 7s2 |
Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 32, 25, 9, 2 |
Melting Point | 1618 K |
Boiling Point | 3383 K |
CAS Number | CAS7440-51-9 |
How to Locate Curium 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 96 to find Curium 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 Curium on periodic table look for cross section of group - and period 7 in the modern periodic table.
Curium History
The element Curium was discovered by G. T. Seaborg, R. A. James and A. Ghiorso in year 1944 in United States. Curium was first isolated by in . Curium derived its name from Pierre Curie, a physicist, and Marie Curie, a physicist and chemist, named after great scientists by analogy with gadolinium.
Discovered By | G. T. Seaborg, R. A. James and A. Ghiorso |
Discovery Date | 1944 in United States |
First Isolation | |
Isolated by |
Prepared by bombarding plutonium with alpha particles during the Manhattan Project
Curium Uses
Curium is mainly used for research, but it could produce more nuclear energy per gram in the future than plutonium.
Curium Presence: Abundance in Nature and Around Us
As Curium is a Synthetic element, the abundance of Curium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body in either not known or they have a very short half life.
Crystal Structure of Curium
The solid state structure of Curium 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 |
---|---|---|
349.6 pm | 349.6 pm | 1133.1 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.
Curium Atomic and Orbital Properties
Curium atoms have 96 electrons and the electronic shell structure is [2, 8, 18, 32, 25, 9, 2] with Atomic Term Symbol (Quantum Numbers) 9D2.
Atomic Number | 96 |
Number of Electrons (with no charge) | 96 |
Number of Protons | 96 |
Mass Number | 247 |
Number of Neutrons | 151 |
Shell structure (Electrons per energy level) | 2, 8, 18, 32, 25, 9, 2 |
Electron Configuration | [Rn] 5f7 6d1 7s2 |
Valence Electrons | 5f7 6d1 7s2 |
Valence (Valency) | 4 |
Main Oxidation States | 3 |
Oxidation States | 3, 4, 5, 6 |
Atomic Term Symbol (Quantum Numbers) | 9D2 |
Bohr Atomic Model of Curium - Electrons per energy level
n | s | p | d | f |
---|
Ground State Electronic Configuration of Curium - neutral Curium atom
Abbreviated electronic configuration of Curium
The ground state abbreviated electronic configuration of Neutral Curium atom is [Rn] 5f7 6d1 7s2. The portion of Curium 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 5f7 6d1 7s2, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Curium
Complete ground state electronic configuration for the Curium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6 5f7 6d1 7s2
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 Curium
Curium atomic radius is -, while it's covalent radius is -.
Atomic Radius Calculated | - |
Atomic Radius Empirical | 176 pm (1.76 Å) |
Atomic Volume | 18.05 cm3/mol |
Covalent Radius | - |
Van der Waals Radius | - |
Neutron Cross Section | 60 |
Neutron Mass Absorption | - |
Spectral Lines of Curium - Atomic Spectrum of Curium
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 Curium
Absorption spectrum of Curium
Curium Chemical Properties: Curium Ionization Energies and electron affinity
The electron affinity of Curium is -.
Valence | 4 |
Electronegativity | 1.28 |
ElectronAffinity | - |
Ionization Energy of Curium
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 Curium
Ionization energy number | Enthalpy - kJ/mol |
---|---|
1st | 581 |
Curium Physical Properties
Refer to below table for Curium Physical Properties
Density | 13.51 g/cm3 |
Molar Volume | 18.05 cm3/mol |
Elastic Properties
Young Modulus | - |
Shear Modulus | - |
Bulk Modulus | - |
Poisson Ratio | - |
Hardness of Curium - Tests to Measure of Hardness of Element
Mohs Hardness | - |
Vickers Hardness | - |
Brinell Hardness | - |
Curium 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).
Curium is a -. Refer to table below for the Electrical properties of Curium
Electrical conductors | - |
Electrical Conductivity | - |
Resistivity | - |
Superconducting Point | - |
Curium Heat and Conduction Properties
Thermal Conductivity | - |
Thermal Expansion | - |
Curium Magnetic Properties
Magnetic Type | - |
Curie Point | - |
Mass Magnetic Susceptibility | - |
Molar Magnetic Susceptibility | - |
Volume Magnetic Susceptibility | - |
Optical Properties of Curium
Refractive Index | - |
Acoustic Properties of Curium
Speed of Sound | - |
Curium Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Curium
Melting Point | 1618 K(1344.85 °C, 2452.730 °F) |
Boiling Point | 3383 K(3109.85 °C, 5629.730 °F) |
Critical Temperature | - |
Superconducting Point | - |
Enthalpies of Curium
Heat of Fusion | - |
Heat of Vaporization | - |
Heat of Combustion | - |
Curium Isotopes - Nuclear Properties of Curium
Curium has 20 isotopes, with between 233 and 252 nucleons. Curium has 0 stable naturally occuring isotopes.
Isotopes of Curium - Naturally occurring stable Isotopes: -.
Isotope | Z | N | Isotope Mass | % Abundance | T half | Decay Mode |
---|---|---|---|---|---|---|
233Cm | 96 | 137 | 233 | Synthetic | ||
234Cm | 96 | 138 | 234 | Synthetic | ||
235Cm | 96 | 139 | 235 | Synthetic | ||
236Cm | 96 | 140 | 236 | Synthetic | ||
237Cm | 96 | 141 | 237 | Synthetic | ||
238Cm | 96 | 142 | 238 | Synthetic | ||
239Cm | 96 | 143 | 239 | Synthetic | ||
240Cm | 96 | 144 | 240 | Synthetic | ||
241Cm | 96 | 145 | 241 | Synthetic | ||
242Cm | 96 | 146 | 242 | Synthetic | ||
243Cm | 96 | 147 | 243 | Synthetic | ||
244Cm | 96 | 148 | 244 | Synthetic | ||
245Cm | 96 | 149 | 245 | Synthetic | ||
246Cm | 96 | 150 | 246 | Synthetic | ||
247Cm | 96 | 151 | 247 | Synthetic | 1.56×10^7 years | AlphaEmission |
248Cm | 96 | 152 | 248 | Synthetic | ||
249Cm | 96 | 153 | 249 | Synthetic | ||
250Cm | 96 | 154 | 250 | Synthetic | ||
251Cm | 96 | 155 | 251 | Synthetic | ||
252Cm | 96 | 156 | 252 | 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) | CAS7440-51-9 |
RTECS Number | - |
CID Number | - |
Gmelin Number | - |
NSC Number | - |
Compare Curium with other elements
Compare Curium with Group , Period 7 and Actinide elements of the periodic table.
Compare Curium with all Group elements
Compare Curium with all Period 7 elements
Compare Curium with all Actinide elements
Frequently Asked Questions (FAQ)
Find the answers to the most frequently asked questions about Curium