Subshells are made up of negative charge clouds called orbitals. Each orbital can hold up to 2 electrons.
Each subshell has a different type of orbital, an s subshell has an s-orbital, a p subshell p-orbitals, etc.
|s||1||1 x 2 = 2|
|p||3||3 x 2 = 6|
|d||5||5 x 2 = 10|
|f||7||7 x 2 = 14|
A s-orbital has a spherical shape.
A p-orbital has a 3-dimensional dumb-bell shape.
There are three p-orbitals, px, py, and pz at right angles to one another.
The structures of d and f-orbitals are more complex.
• There are five d-orbitals.
• There are seven f-orbitals.
Why do orbitals have 2 electrons?
Electrons have negative charge and will repel each other. However they have a property called spin.
The two electrons in an orbital will have different spins that helps overcome any repulsive energy.
Orbitals can be represented by a box with electrons represented by arrows within the box.
The spin of the electron is shown by having the arrow point either up or down.
Within an orbital the 2 arrows can't point in the same direction, the electrons must have opposite spin.
This video shows an introduction to Orbitals
This video shows more intuition on orbitals. Touching on electron configuration.