|Matters and Properties of Matters|
|Atomic Structure with Examples|
|--Electron Configuration with Examples|
|--Orbitals and Placing Electrons to Orbitals with Examples|
|--Atomic Structure Cheatsheet|
|The Mole Concept with Examples|
|Gases with Examples|
|Chemical Reactions with Examples|
|Nuclear Chemistry (Radioactivity)|
|Acids and Bases|
|Rates of Reactions (Chemical Kinetics)|
|Exams and Problem Solutions|
Electron Configuration with Examples
Electrons are not placed at fixed positions in atoms, but we can predict approximate positions of them. These positions are called energy levels or shells of atoms.
1st energy level has;
2nd energy level has;
3rd energy level has;
Following pictures show location of electrons of atoms O and Mg.
Number of electrons at the outer shell of atom gives us following classification.
Electron configuration of atom shows, shells, sub shells and number of electrons in sub shells. We examine electron configuration with following examples.
Example: Helium 2
1 is the principal quantum number or energy level (shell)
s is the sub-level or sub shell (Capacity of s sub shell is 2 electron)
2 shows the number of electrons in the s sub shell
Example: Chlorine 17
Coefficients 1, 2, 2, 3, and 3 are energy levels of Cl. As you can see "p" sub shell can have maximum 6 electrons.
Superscripts 2, 2, 6, 2 and 5 are electrons in the sub shells "s" and "p".
Example: Bromine 35
As you can see "d" sub shell can have maximum 10 electrons.
Example: Tantalum 73
As you can see "f" sub shell can have maximum 14 electrons.