Technetium Electron Configuration: 7 Easy Steps to Follow!

Technetium has the atomic number 43 and the letter Tc as its symbol Let us find the electron configuration of technetium below.

Technetium has an atomic mass of 97 amu with an electron configuration of [Kr]4d5 5s2. It has a melting point and boiling point of 2157 °C and 4265 °C respectively. It is the first element created synthetically. Technetium is a transition metal with a silvery-grey colour.

Let us discuss many facts regarding Technetium electron configuration, orbital diagram, ground-state electron configuration and unabbreviated electron configuration.

How to write Technetium electron configuration?

The technetium atom contains 43 electrons. The following procedures are used to arrange these electrons inside the technetium atom.

Step 1: First of all write the shell number:

There are a total of 5 electron shells in the Tc. The structure of these 5 shells is 2, 8, 18, 13, and 2 electrons. Technetium atom contains a total of 43 electrons, and it has a valence electron count of 7.

Step 2: List the orbitals with their symbol:

The orbitals are denoted by the symbol S, P, D, and F orbitals are present in these 5 shells at this stage, allowing electrons to arrange like 1s, 2s, 2p, 3s, 3p, 3d, 4s, 4p, 4d, 4f, 5s, and so on

Step 3: Arrange shell/orbital according to Aufbau’s principle:

The Aufbau principle states the sub-energy levels of atoms. The range of “l” is 0 to (n – 1). The s-subshell has an orbital number of 1, while the p, d, and f subshells have 3, 5, and 7 respectively. The maximum number of electrons in an orbital is two.

Orbitals Number of electrons 
occupied
s 2
p 6
d 10
f 14
Orbital with electron

Step 4:  Electrons are arranged according to Hund’s rule and Pauli exclusion principle

The Pauli exclusion principle states that the electron pairing then continues in the opposite direction, despite Hund’s maximum multiplicity rule’s statement that higher spin multiplicities are more stable. Tc would have 5 unpaired electrons due to its 4d5 5s2 structure, which has 7 valence electrons.

Step 5: Then overall electron configuration with subscripts:

Then, based on the electron’s greatest capacity in the orbitals, subscripts are assigned to them. The following list of final electron configurations is written in ascending order:  1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d5 5s2.

Technetium electron configuration diagram

There are 43 electrons in a technetium atom, and they are distributed as shown below in the diagram.

technetium electron configuration
Image Credits: Technetium Ground State by
 Pumbaa CC-BY-SA-2.0-UK

Technetium electron configuration notation

The notations for technetium electron configuration are as follows: [Kr]4d5 5s2.

The above notation demonstrates that the technetium atom’s five shells are filled with 43 electrons. It has five electrons in the d-shell and two in the s-shell.

Technetium unabbreviated electron configuration

Technetium atom’s unabbreviated electronic configuration is as follows: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, and 4d.

Orbitals Number of
electrons 
occupied by
each orbital
1s 2
2s 2
2p 6
3s 2
3p 6
4s 2
3d 10
4p 6
5s 2
4d 5
Unabbreviated Technetium electron configuration

Ground state Technetium electron configuration

In its ground state, technetium has an electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d5 5s2 or [Kr] 4d5 5s2.

Excited state of Technetium electron configuration

In its excited state, technetium exhibits an electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d4 5s2 or [Kr] 4d4 5s2.

Ground state Technetium orbital diagram

Technetium‘s ground state electron configuration is [Kr]4d5 5s2, with each full electron pointing in both a clockwise and an anticlockwise direction.

technetium electron configuration
Ground state orbital diagram

Conclusion

Technetium was generated by colliding molybdenum atoms with deuteron particles. It is the lightest element with radioactive isotopes. The most common places to find Tc in nature are uranium and thorium ores. It naturally occurs as a result of fission, or in molybdenum ores.

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