Electron Configuration

The electron configuration is written by locating all the electrons of an atom or ion in their orbitals or energy sublevels.

Recall that there are 7 energy levels: 1, 2, 3, 4, 5, 6 and 7. And each of them has, in turn, up to 4 energy sub-levels called s, p , d and f.

Thus, level 1 only contains sublevel s; level 2 contains syp sublevels; level 3 contains sub-levels s, p and d; and levels 4 to 7 contain sublevels s, p, d and f.

The electron configuration

The electron configuration of the elements indicates the way in which the electrons are ordered in the different energy levels, what are called the orbits, or simply, it initiates the way in which the electrons are distributed around the nucleus of their atom.

To calculate the distribution of electrons in the different energy levels, the Electron configuration takes the quantum numbers as a reference or simply uses them for the distribution. These numbers allow us to describe the energy levels of electrons or a single electron, they also describe the shape of the orbitals it perceives in the distribution of electrons in space.

Element Configuration Table

The most consulted elements!

The Electron configuration, also called Electron distribution Is periodic adjustmentbecomes the way electrons manage to structure themselves, organize themselves and communicate within an atom following the model of Electron shells, where all the wave functions of the system are expressed in the form of an atom.

Thanks to the Electron configuration, it is possible to establish the properties of combination from a chemical point of the atoms, thanks to this, it is that the place which corresponds to it in the periodic table is known. This configuration indicates the order of each electron in the different energy levels, i.e. in the orbits, or simply shows their distribution around the nucleus of the atom.

Why is electron configuration important?

In itself, the Electron configuration comes to show the position that each electron occupies in the nuclear envelope, thus identifying the energy level in which it is and the type of orbit. The electron configuration It depends on the type of chemical element you want to study.

The farther the electron is from the nucleus, the higher this energy level will be. When the electrons are in the same energy level, this level takes the name of energy orbitals. You can check the Electron configuration of all elements using the table that appears above this educational text.

The Electron configuration of the elements also uses the atomic number of the element which is obtained through the periodic table. It is necessary to know what an electron is, in order to study this valuable topic in detail.

This identification is carried out thanks to the four quantum numbers that each electron has, namely:

• magnetic quantum number: shows the orientation of the orbital in which the electron is located.
• principal quantum number: it is the energy level in which the electron is located.
• Spin quantum number: refers to the spin of the electron.
• Azimuthal or secondary quantum number: it is the orbit in which the electron is located.

Objectives of Electron configuration.

The main purpose of electron configuration is to clarify the order and energy distribution of atoms, especially the distribution of each energy level and sublevel.

Types of Electron configuration.

• Default configuration.  This Electron configuration is achieved thanks to the table of diagonals, here the orbitals are filled as they appear and always following the diagonals of the table, always starting with 1.
• Expanded configuration. Thanks to this configuration, each of the electrons of an atom is represented using arrows to represent the spin of each. In this case, the filling is done taking into account Hund’s maximum multiplicity rule and Pauli’s exclusion principle.
• condensed configuration. All levels that become full in the standard configuration are represented by a noble gas, where there is a correspondence between the atomic number of the gas and the number of electrons that filled the final level. These noble gases are: He, Ar, Ne, Kr, Rn and Xe.
• Semi-expanded configuration. It is a mix between the expanded configuration and the condensed configuration. In it, only the electrons of the last energy level are represented.

Key points for writing the electron configuration of an atom.

• You must know the number of electrons that the atom has, for that you only have to know its atomic number since this is equal to the number of electrons.
• Place the electrons in each energy level, starting with the closest.
• Respect the maximum capacity of each level.

Steps to obtain the electron configuration of an element

The first thing to know is the atomic number of the element to be studied, which is represented by the capital letter Z. This number can be found in the periodic table, which corresponds to the total number of protons that each atom of said element has.

In this case, the atomic number in the periodic table is always indicated in the upper right box, for example, in the case of hydrogen, it will be the number 1 that is observed in the upper part of this box, while its atomic weight or masico number, is the one that is enclosed in the upper part but on the left side.

The use of this atomic number causes its configuration to be determined through the use of quantum numbers and the respective distribution of electrons in the orbit

Here are some examples of element configuration.

• Hydrogen, its atomic number is 1, i.e. Z=1, therefore, Z=1:1s^a .
• Potassium, its atomic number is 19, so Z=19: 1s^{of them}2s^{of them}2P⁶3s^{of them}3p⁶4s^{of them}3d^ten4p^a.

Electron dissemination.

It corresponds to the distribution of each of the electrons in the orbitals and sub-levels of an atom. Here the Electron configuration of these elements is governed by the Moeller diagram.

In order to determine the Electron distribution of each element, only the notations must be written diagonally starting from top to bottom and from right to left.

Classification of elements according to Electron configuration.

All chemical elements are classified into four groups, they are:

• noble gases. They completed their electron orbit with eight electrons, not counting He, which has two electrons.
• transition elements. They have their last two orbits incomplete.
• Internal transition elements. These have their last three orbits incomplete.
• representative element. These have an incomplete outer orbit.

Working with Elements and Compounds

Thanks to the Electron configuration of the elements, it is possible to know the number of electrons that the atoms have in their orbits, which becomes very useful when building ionic, covalent bonds and knowing the valence electrons, this last corresponds to the number of electrons that the atom of a certain element has in its last orbit or shell.

Desnity of Elements

All matter has mass and volume., however the mass of different substances occupies different volumes.