Electron configurations
Valence electrons are electrons used in forming bonds and are in the outer shell of an element.
The bond that occurs can be either an ionic bond or a covalent bond
Valence electron determination using electron configurations.
The main group elements usually have valence electron configurations in the s and p subshells
While the transition elements in the subshells (n-1) d
Further explanation
The location of the elemental groups in the periodic system is determined by the number of valence electrons filling the last sub-shell
The period of an element is determined from the valence shell (the biggest main quantum number (n) )
In an atom, there are levels of energy in the shell and subshell
This energy level is expressed in the form of electron configurations.
Writing electron configurations starts from the lowest to the highest sub-shell energy level. There are 4 sub-shells in the shell of an atom, namely s, p, d, and f. The maximum number of electrons for each subshell is
s: 2 electrons
p: 6 electrons
d: 10 electrons and
f: 14 electrons
Charging electrons in the subshell uses the following sequence:
1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s², 4d¹⁰, 5p⁶, 6s², etc.