Question

Describe the electron configuration of an atom using principal energy level, sublevels, orbitals, and periodic table. Give one example others may not think about and why you made this selection.

Answer 1

Silicon(Si) is a very a very unique element with atomic number 14. We see it all around us in the form of sand which has the general formula of $SiO_2$ .

The electronic configuration of Silicon (Si) atom is

$1s^22s^22p^63s^23p^2$ .

The principal energy levels are filled in the following way.

We can make a chart showing all the level, sublevels and orbitals with number of electrons in them for Si.

Principal Energy Level	Sublevel	Number of Orbitals	Number of electrons filled
n=1	s	1	2
n=2	s p	1 3	2 6
n=3	s p d	1 3 5	2 2 0

For n =1, the sublevels can be only an s orbital with l=0, because allowed values of l's are from 0 to n-1.

For n=2, the allowed sublevels are s and p with l values of 0 and 1.

For n=3, the allowed sublevels are s, p and d with l values 0, 1 and 2.

It has the core of Neon with 5 extra electrons in the principal energy level with n=3. Hence, it's electronic configuration can also be written in short as $[Ne]3s^23p^2$ .

The reason for its selection lies in its unique properties. Its application in semiconductors and computer chips makes it a very key element in the modern world of technology.

It is very similar to its group member Carbon with respect to bonding, yet it is very unique because of presence of an empty 3d orbital, unlike Carbon. Like carbon it can form many different bonds, but most of the time it is tetravalent. It forms the core structure of variety of minerals found on earth's crust. The core unit of silicates $SiO_4^{4-}$ can bind in many ways to form structures like neosilicates and tectosilicates.