Question

1) Show the obrital-filling diagram for S (sulfur). Stack the subshells in order of energy, with the lowest-energy subshell at the bottom and the highest-energy subshell at the top.

2) Show the orbital-filling diagram for Br (bromnie). Stack the subshells in order of energy, with the lowest-energy subshell at the bottom and the highest-energy subshell at the top.

Answer 1

You want electron configuration.
Atomic # is the number of electrons that a particular element has.

Here's the order of the energy shells. The lowest shell in energy is 1s, and by following the arrows on this chart, you get to the highest shell, no matter what element you configure.
http://www.mwt.net/~bionorse/electron%20...

The 4 shells, S,P,D, & F, all can hold different #s of electrons in sets of 2.
S holds 1 set of 2 (2 total)
P holds 3 sets (6)
D holds 5 sets (10)
F holds 7 sets (14)

On the periodic table, Groups 1-2 electron configuration ends in S, transition metals end in D, Groups 3-8 end in P and the most of the 2 lines under the main table end in F. This periodic table also does electron configuration.
http://www.ptable.com

Doing electron configuration is easy. You just have to total then atomic number in shells.
They write shells/# electrons by simply writing the # and letter of the shell, then the # of electrons. For example, in 1s2, 1s is the shell name, and 2 is the number of electrons in the shell. By the way, can you guess which element has a configuration of 1s2?? (Hint, the atomic # is 2)

Helium is 1s2.
K, element 19, is 1s2 2s2 2p6 3s2 3p6 4s1... Why? Well because this is the order the shells are in, and 2+2+6+2+6+1 = 19, K's atomic #. Sound easy?
It is.

So let's look at Sulfur. It's Group 6, # 16, so what does that tell you?
I hope you looked above and said the configuration should end in P. Because it does.
Now just add the numbers in the shells in the proper order.
1s2 2s2 2p6 3s2 3p........ (fill in the blank here)... 2+2+6+2 = x .... 16-x = ???
I know you can add and subtract...
You got 12 for x, right? So 16-12 = 4...
So it's 3p4.

Hund's rule states that in electron shells, subshells must be filled singly before being completely filled... So this means that in the X, Y and Z axis subshells of the 3p shell, the electrons fill like this...
X 1-
Y 1-
Z 1-
X 11
Therefore, the X subshell is full, but Y and Z subshells are not, since there are 4 electrons in 3 subshells.