Write electronic configuration of element

How to write an electronic configuration?

For the purpose of writing the electronic configuration of any atom, you must know the atomic number of that atom, whereas the number of electrons of an atom is equal to their atomic number (number of protons) if electrically equivalent.

Well it should we know that the basic process in writing an electronic structure of an atom is that we start by filling the orbitals with electrons of the less energy and then the most energy, thus where they are arranged as follows:

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d

In the case of secondary levels containing more than one orbital such as levels (p, d and f) electrons enter individually in these orbitals to avoid electric repulsion between charges according to the Hund’s rule.

This rule states that there is no duplication between two electrons in the secondary energy level only after orbitals occupies an individual firstly.

Even if all orbitals of the secondary level now have an one electron in each of them as at the secondary level p3

then the fourth electron enters to double with one electron that preceded it to make full orbitals in the secondary level p4    

and to overcome the repulsion between the two electron charges within a single orbital, the two electrons are represented by two opposite arrows.

Example 1

Write the electronic configurations for the following elements:

V= 23

K=19

Ar= 18

Solution:

If we note in the previous example of the elements that 23V, 19K That the electronic configuration of the first 18 electrons of them is (1s2 2s2 2p6 3s2 3p6). This is the electronic configuration of [Ar] so we can simplify this configuration. So we will write the order of the first 18 electrons of potassium 19K and vanadium 23V as well as for the elements beyond which to  [Kr]

As follows:

Example 2

Write the electronic configuration of the elements

Cu= 29

Cr= 24

Solution:

Note that level d needs an electron to become half saturated and atoms when their secondary levels are half full or full be more stable so we write the configuration as follows:

Example 3

Write the electronic configuration for:

 Ag= 47

 Kr= 36

Solution: