Cobalt

Written by J.A Dobado | Last Updated on April 22, 2024

Cobalt element periodic table

Cobalt is a chemical element with the symbol Co and atomic number 27. It is a hard, lustrous, and silver-gray transition metal that is found in small amounts in many minerals, including cobaltite, which is the primary source of cobalt. It is extracted from cobaltite through a process called roasting and reduction.

Medieval German miners often mistook cobalt ores for precious metals. Thus, they became ill when they tried to purify them, due to the arsenic gas released in the process. Pure cobalt is added to steel and other alloys to make them stronger. Alloys containing cobalt are used in jet engine blades and in artificial joints, such as hip and knee joints. Cobalt is one of the few elements that can be used to make a permanent magnet. The strongest permanent magnets are made of a strong alloy of cobalt, nickel, and aluminum, called alnico. In addition, a radioactive isotope of cobalt, called cobalt-60, is produced in nuclear reactors. This isotope is widely used to irradiate food, a process by which food is exposed to a small dose of radiation to kill harmful germs.

Cobalt has many important uses, including in the production of cobalt alloys, which are used in the aerospace, defense, and other industries. It is also used in the production of magnets and other magnetic materials. Cobalt can also produce an intense shade of blue. Thus, cobalt blue paints and dyes are formed by reacting aluminum with cobalt oxide.

Cobalt element periodic table

Electron configuration

The electron configuration of an element describes the arrangement of electrons in the atoms of that element, and be used to predict its chemical properties and reactivity.

In the electron configuration notation, the letters "s", "p", "d", and "f" represent the different types of atomic orbitals, and the superscripts indicate the number of electrons in each orbital. The orbitals are filled in a specific order, starting with the lowest energy orbital and working up.

electron configuration of element Co

Emission spectra

Each element in the periodic table presents its own unique emission spectra, which is determined by the energy levels of its electrons. When an electron in an atom is excited to a higher energy level, it can de-excite by emitting a photon of light with an energy equal to the difference between the two levels. This results in a characteristic emission line in the spectra (which corresponds to specific wavelengths of light). These spectra are usefull to identify the elements present in a sample.

emmision spectra of element Co

Symmary of properties (Co)

Atomic weight58.933194(4)
Discoverer (year)Brandt, Georg (1735)
Natural formmetallic solid (hexagonal)
Electron configuration[Ar] 3d7 4s2
M.p. (ºC)1495
B.p. (ºC)2870
Earth's crust abundance (ppm)25
Isotope (abundance %)59Co (100)
Density (g/cm3)8.9
vdW radius (pm)200
Covalent radius (pm)118
Electronegativity (Pauling)1.91
Vaporisation enthalpy (Kj/mol)382.40
Fusion enthalpy (kJ/mol)16.20
Specific heat capacity (J/g·K) at 25ºC and 1 at0.42
Thermal conductivity (W/cm·K) at 25 ºC and 1 at1.000
Oxidation number+3, +2
Electronic affinity (eV)0.66
1st Ionization energy (eV)7.8810

Definition of terms in the previous table

  • Atomic weight: The average mass of an element's atoms, typically given in atomic mass units (amu).
  • Natural form: The most stable and abundant form of an element that occurs naturally in the environment.
  • Electron configuration: The arrangement of electrons in an atom or molecule.
  • Melting point: The temperature at which a solid substance turns into a liquid.
  • Boiling point: The temperature at which a liquid substance turns into a gas.
  • Earth's crust abundance (ppm): The concentration of an element in the Earth's crust, typically given in parts per million (ppm).
  • Isotope (abundance %): A variant of an element that has the same number of protons in the nucleus, but a different number of neutrons. The abundance of an isotope is the percentage of the isotope in a sample of the element.
  • Density (g/cm3): The mass of a substance per unit volume.
  • vdW radius (pm): The radius of an atom or molecule as predicted by the van der Waals model, typically given in picometers (pm).
  • Covalent radius (pm): The distance from the center of an atom to the center of another atom with which it is bonded covalently, typically given in picometers (pm).
  • Electronegativity (Pauling): A measure of an atom's ability to attract electrons in a chemical bond, based on the Pauling scale.
  • Vaporisation enthalpy (kJ/mol): The amount of energy required to convert a substance from a liquid to a gas at a constant temperature.
  • Fusion enthalpy (kJ/mol): The amount of energy required to convert a substance from a solid to a liquid at a constant temperature.
  • Specific heat capacity (J/g·K) at 25ºC and 1 at: The amount of heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius at a constant pressure.
  • Thermal conductivity (W/cm·K) at 25 ºC and 1 at: The ability of a substance to conduct heat, typically given in watts per centimeter per kelvin.
  • Oxidation number: A positive or negative integer that represents the number of electrons that an atom has gained or lost in a chemical compound.
  • Electronic affinity: The energy change associated with adding an electron to a neutral atom to form a negative ion.
  • 1st Ionization energy: The energy required to remove the most loosely bound electron from a neutral atom.
 

Back to the Periodic Table of the Elements.

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