Electron configuration

Orbitals

• electrons are not actually particles - they can be refered to as clouds or waves of negative charge.

• electrons occupy an areas we refer to as an orbital

• and orbital is are volumes of space surrounding the nucleus where there is a 95% chance we can find an electron

• for each energy level there are specific numbers of orbitals it can hold

Histroy of the orbital:

We don’t actually know exactly where the electron is ues to the uncertainty principle. BUT we can get a rough idea by calculating prbability of finding an electron around the nucleus - and use this calcualtion to find a region if space which 95% likely contains an electron.

we call this region of space and orbital

Shapes + types of orbitals:

s orbitals~

• are spherical in shape

• 1 orbital

• can hold only 2 electrons

p orbitals~

• are shaped like a dumbbell

• 3  sublevels of orbitals

• can hold up to 6 electrons

d orbitals~

• various shapes

• 5 sublevels of orbitals

• can hold up to 10 electrons

f orbitals~

• various shapes

• 7 sublevels of orbitals

• can hold up to 14 electrons

Rules

1. Electron will occupy the orbital starting from the lowest every level if they can.

2. Each orbital can hold up to 2 electron which will have opposite spins.

3. Electrons are a bit repulsive so in an orbital they will each fill the subtype before pairing up.

How it works: in terms of a new way of writing electron arrangements…

Eg: write the shorthand electron configuration for Kr (Krypton)

2.8.8.8.8.2 → however this means that it is in Group 2, Period 6… which a completely different element.

sooooo instead we do this:

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰4p⁶

^{here are some other examples..}