Elements are arranged on the periodic table of the elements based on various properties such as electron configuration. An ion of a group 2 (2A) element will MOST likely have an electron configuration similar to that of a neutral atom from which group?
Answers
Introduction
In general when filling up the electron diagram, it is customary to fill the lowest energies first and work your way up to the higher energies. Principles and rules such as the Pauli exclusion principle, Hund’s rule, and the Aufbau process are used to determine how to properly configure electrons. The Pauli exclusion rule basically says that at most, 2 electrons are allowed to be in the same orbital. Hund’s rule explains that each orbital in the subshell must be occupied with one single electron first before two electrons can be in the same orbital. Lastly, the Aufbau process describes the process of adding electron configuration to each individualized element in the periodic table. Fully understanding the principles relating to electron configuration will promote a better understanding of how to design them and give us a better understanding of each element in the periodic table. How the periodic table was formed has an intimate correlation with electron configuration. After studying the relationship between electron configuration and the period table, it was pointed out by Niels Bohr that electron configurations are similar for elements within the same group in the periodic table. Groups occupy the vertical rows as opposed to a period which is the horizontal rows in the table of elements.
S, P, D, and F Blocks
It is easy to see how similar electron configurations are in a group when written out. (Allow “n” to be the principal quantum number.) Lets first take a look at group 1 atoms. Group 1 atoms are the alkali metals. Let n=1. Notice the similar configuration within all the group 1 elements.
Group
Element
Configuration
1
H
1s1
1
Li
[He]2s1
1
Na
[Ne]3s1
1
K
[Ar]4s1
1
Rb
[Kr]5s1
1
Cs
[Xe]6s1
1
Fr
[Rn]7s1
Now consider group 16 elements. These elements also will also have similar electron configurations to each another because they are in the same group; these elements have 6 valence electrons.
Group
Element
Configuration
16
O
[He]2s22p4
16
S
[Ne]3s23p4
16
Se
[Ar]3d104s2 4p4
16
Te
[Kr]4d105s2 5p4
16
Po
[Xe]4f14 5d106s2 6p4