Describe the filling or lack thereof of sublevels for the electron configurations of the....?

Question

....representitive elements

Answer 1

Start from the bottom and work up. For the representative elements, (I think this is an old-fashioned expression for the s- and p-block) this means using

1s<2s<2p<3s<3p<4s<3d<4p<5s ...

Within each sublevel (in this case, this only affects the p sublevels, as you don't have any choice with the s) you put electrons into different orbitals within the sublevel as long as you can, and put as many as possible in with their spins pointing the same way.

Principles involved:

Aufbauprinzip (German for building-up principle), start at the bottom and work up.
Exclusion principle: no two electrons can have exactly the same set of quantum numbers, which is why each orbital can hold no more than two electrons.
Hundt's Rule: other things being equal, set things up with the maximum number of unpaired spins. This helps the electrons, which repel each other, keep out of each other's way.

Hope this helps!