Calcium

Calcium element periodic table

Calcium is a chemical element with the symbol Ca and atomic number 20. It is a soft, gray, alkaline earth metal that is the fifth most abundant element on Earth. Calcium is a component of many minerals, including limestone, gypsum, and fluorite. It is highly reactive and forms compounds with almost all other elements.

Calcium is the most abundant metal in the human body. It is also the fifth most common element on Earth. It occurs in many minerals, such as calcite and aragonite, which are formed from calcium carbonate. Bones in animal skeletons contain calcium phosphate. Also, the hard outer layers of many other animals, such as the shells of sea snails, are made of calcium carbonate. This element is very important in our diet, we obtain it mainly in dairy products. Antacid tablets, used to treat indigestion, contain calcium carbonate. This compound reacts with acid in the stomach.

Calcium compounds are also common in building materials. Plasterboard, which is used to smooth walls, writing chalk. Calcium oxide is an important ingredient in cement and aids in the setting process. Calcium has many important uses as a component of certain medications, and in the production of steel and other metals.

Calcium 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 Ca

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 Ca

Symmary of properties (Ca)

Atomic weight 40.078(4)
Discoverer (year) Davy, Humphry (1808)
Natural form metallic solid (face-centred cubic)
Electron configuration [Ar] 4s2
M.p. (ºC) 839
B.p. (ºC) 1484
Earth's crust abundance (ppm) 41500
Isotope (abundance %) 40Ca (96.941), 42Ca (0.647), 43Ca (0.135), 44Ca (2.086), 46Ca (0.004), 48Ca (0.187)
Density (g/cm3) 1.55
vdW radius (pm) 231
Covalent radius (pm) 174
Electronegativity (Pauling) 1.36
Vaporisation enthalpy (Kj/mol) 150.00
Fusion enthalpy (kJ/mol) 8.54
Specific heat capacity (J/g·K) at 25ºC and 1 at 0.65
Thermal conductivity (W/cm·K) at 25 ºC and 1 at 2.010
Oxidation number 2
Electronic affinity (eV) 0.02
1st Ionization energy (eV) 6.1132

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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