[Shamen]

Could someone explain to me, what exactly are sub-shells, and also, what s-,p- and d- are. Thanks.

[TakeItEasy]

I think the answers are there in the text book.

[Donaldson Tan]

each electron shell is furthur subdivided. each subdivision is call a subshell. each subshell has different energy level.

the first shell contains 1 subshell - s.
the second shell contains 2 subshell - s,p
the third subshell contains 3 subshells - s,p,d

can u see a co-relation? the order of the shell (1st, 2nd, 3rd, etc) corresponds to the number of subshells. By default, the lowest energy subshell within the same shell is called s. the next highest is p, follow by d, f, h, etc subsequently. the notation used is in fact every even numbered letter after d.

the rank of energy level for each subshell follows:
1s < 2s < 2p < 3s < 3p <4s < 3s ...
[u can find this rank in any general or physical chemistry textbook]

each subshell consist of different odd number of orbitals. Each orbital holds a maximum of 2 electrons. This is in accordance with Pauli's Exclusion Principle. The s subshell contains 1 orbital. The p subshell contains 3 orbitals. The d subshelll contains 5 orbitals. The f subshell contains 7 orbitals. Can u see a co-relation between the rank of the subshell (s,p,d,f) with the number of orbitals (1,3,5,7)? Hint: odd numbers

The orbitals are filled up with lowest energy given priority. This is known as the Aufbau's Principle. Practise writing electronic configurations. It will be very helpful for you to learn this particular aspect of chemistry,

I hope this proves helpful for u.