Chromium Electron Configuration: 9 (Easy Step-by-Step Guide)

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Chromium belongs to group 6th of the periodic table. Let us have an eye at the electronic configuration of chromium.

Chromium is naturally found in chromite, rocks, and soil as a combined form. Chromium belongs to the d-block. It can exist up to +6 oxidation, out of which 3+ and 6+ are mostly formed. Chromium is a strong oxidizing agent; melting and boiling points are very low because of its less metallic character.

In this article, we will discuss chromium’s facts, like its ground state, excited state electronic configurations, and orbital diagram.

How to write the chromium electron configuration

There are 24 electrons present in the Cr atom. According to Aufbau’s principle, the electrons get filled in the order of increasing energies. Then after the electrons get paired by following Hund’s rule, this pairing takes place in the reverse direction following Pauli’s exclusion principle.

chromium electron configuration diagram

The Cr atom has 24 electrons; the electrons get filled with the lowest energy orbital first and later the remaining.

  • The electrons get filled into the first and foremost lowest energy orbital 1S, having a maximum capacity of 2 electrons.
  • Then after 2S orbital gets filled with maximum efficiency of 2 electrons.
  • In the same way, 2P, 3S, and 3P orbital get filled with maximum efficiency of 6 electrons,2 electrons, and 6 electrons, respectively.
  • After that, the 4s orbital gets filled with only one electron because of donating 1 electron to the 3d orbital to attain stability by half-filled (3d5) electronic configuration.

The electronic configuration diagram of the Cr atom:

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Electronic Configuration Diagram

Chromium electron configuration notation

The Cr atom electronic configuration notation is depicted as – [Ar] 4s13d5. The Cr atom consists of 24 electrons, out of which 18 come under Argon gas configuration, and the remaining three are allocated in 4s orbital with 1 electron and 3d orbital with 5 electrons.

chromium unabbreviated electron configuration

The unabbreviated electronic configuration of the chromium atom is 1S22S22P63S23P63d54S1. The unabbreviated electronic configuration is termed the electronic configuration using noble gas configuration. This unabbreviated noble gas configuration starts from first and foremost 1S orbital and then after the remaining.

ground state chromium electron configuration

  • The ground state electronic configuration of the chromium atom is 1S22S2 2P63S2 3P63d5 4S1.
  • This ground-state electronic configuration is generally stated as the electronic configuration of an element in its ground state (lowest energy state).

the excited state of chromium electron configuration

The excited state electronic configuration of the chromium atom is 1S22S2 2P63S2 3P63d5 4S0 as the last valency electron jumps to the next energy level by absorbing energy.

ground state chromium orbital diagram

The ground state orbital diagram of chromium is:

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Ground state electronic configuration

chromium 3+ electron configuration

The electronic configuration of Cr3+ is 1S22S2 2P63S2 3P63d34S0. The number of electrons in the Cr atom is 24, and its outermost atomic orbitals are 4s13d5. So removed an electron from the 4 orbital and 2 electrons from the 3d-orbital  to get the Cr3+ electronic configuration.

chromium 6+ electron configuration

The electronic configuration of Cr6+ is 1S22S2 2P63S2 3P63d04S0. Here from the electronic configuration of chromium 1S22S2 2P63S2 3P63d5 4S1, one electron has been removed from the outermost 4S orbital and the remaining 5 electrons removed from the next outermost orbital 3d to get the electronic configuration of Cr6+.

Conclusion

Chromium is very hard and is in third place after diamond and boron. Isotopes of chromium are 52Cr, 53Cr, and 54Cr; among these, 52Cr most abundant. Cr can be used for hardening steel, producing stainless steel, and many alloys. It is mainly used in metallurgy as paints and dyes to impart color.

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