yesterday's lesson was about the atomic structure - i totally forgot to make my own notes, but luckily though i understood what Mr. Tan taught us. 

ooohoooh number of shells is now Principal Quantum Shell. ^^

Basically sub-shells are 3D shells WITHIN shells, where electrons can be found around 95% of the time. The 5% accounts for electrons that may have escaped the sub-shell, but Mr. Tan said that we would be focusing on stuff INSIDE the sub-shell, rather than outside.
We learnt 2 sub-shells in detail, although there are 4 to be learnt - s, p, d &&&& f

S orbitals are spherical in shape and appear like ya know in...1s 

P orbitals exist in 3s - Px, Py & Pz. Uhh i think it's because they lie on their respective axes - x, y & z. They look like dumbells (weirdo chemistry >.>). They only appear on shells after the first shell, as shell #1 is used for S sub-shells. 

gotta complete tutorial 3 too.

:)