Orbital:It is the actual region of space occupied by an electron in a particular energy level.
There are 4 letters which are s,p,d,f refer to the 4 different kinds of orbitals.Look at the picture, each circle represents one orbitals.
An s-type subshell consists of ONE s-orbital
A p-type subshell consists of THREE p-orbitals
A d-type subshell consists of FIVE d-orbitals
An f-type subshell consists of SEVEN f-orbitals.
How to write electronic configurations for neutral atoms?
Aufbau principle told us we should always start with the lowest energy level.
First, you should know how many electrons you have. Next, start at the lowest energy level(1s) and keep adding until you have no left.
How to write electron configurations for IONS?
1.For a negative ion:Add the electron(s) which equal(s) to the charge to the last subshell if it is unfilled.
2.For a positive ion:You should do neutral configuration first, remove the electrons which is in the most out shell.
Orbital Box Notation
Orbital Box Notation is the way shown in the orbital diagram below
Spectroscopic notation (more commonly used, but the "long way")
this is the was it is written under the electron configuration below on the right.
Core Notation
It is a short way to show the electron configuration by using core and the outer elements.You can write out just the ones since the last noble gas.
For example, find carbon in the periodic table, then go backwards till you find the noble gas.For C, the noble gas is He.So the core notation of carbon is [He]2s²2p².
C: 1s²2s²2p²
For C, box notation is also easy for you!
Here is a picture can make you easier to understand the relationship between the periodic table and Electronic Configuration.
BUT NOTICE!!!!
Predicting the Number of Valence Electrons
Valence electrons: Outermost electrons of an atom (in highest energy level). These determine the chemical properties of an element.
Valence Electrons are all the electrons in an atom EXCEPT those in the core, or in the filled d- or f- subshells.
Example.
O 1s²2s²2p6
core notation:[He]2s²2p6
So the Valence Electrons of O is 8.
YOU UNDERSTAND?
