electronic structure & bonding and structure summary

ELECTRONIC STRUCTURE
Electrons have fixed energies and move around the nucleus in shells / energy levels
(principal quantum number)
Shells further from the nucleus have a higher energy and a larger principal quantum
number than shells closer to the nucleus
Shells are divided into sub shells
Different electron shells have different numbers of sub shells with a different energy
Sub shells have different number of orbitals that can hold up to 2 electrons
Sub shells : s-, p-, d-, f- .
S: 1 orbital =2 e-
P: 3 =6e-
D: 5 = 10e-
F: 7 =14e-

An orbital is an area around the nucleus in which an electron moves in
Orbitals within the same sub-shell have the same energy
2 electrons in a orbital spin in opposite directions = spin pairing
S orbital is spherical
P orbital is dumbbell shaped ( 3p orbitals at right angles to one another)

Shells and total number of electrons
1st: 2
2nd: 8
3rd: 18
4th: 32 (sum of all other electrons in other orbitals)

, ELECTRONIC CONFIGURATION (number of electrons and how they’re arranged)




1 box= orbital
1 arrow = electron
Up & down arrows = electrons spinning in opposite directions