This is an Ascii table for the elements on the 4th period (row) of the periodic table, and distribution of electrons in each orbit.
+---------+----------+---------+---------+----------+---------+
| | | | | | |
+---------+----------+---------+---------+----------+---------+
| Element | Atomic # | Shell 1 | Shell 2 | Shell 3 | Shell 4 |
| K | 19 | 2 | 8 | 8 | 1 |
| Ca | 20 | 2 | 8 | 8 (9?) | 2 (1?) |
| Sc | 21 | 2 | 8 | 9 | 2 |
| Ti | 22 | 2 | 8 | 10 | 2 |
| V | 23 | 2 | 8 | 11 | 2 |
| Cr | 24 | 2 | 8 | 13 | 1 |
| Mn | 25 | 2 | 8 | 13 | 2 |
| Fe | 26 | 2 | 8 | 14 | 2 |
| Co | 27 | 2 | 8 | 15 | 2 |
| Ni | 28 | 2 | 8 | 16 | 2 |
| Cu | 29 | 2 | 8 | 18 | 1 |
| Zn | 30 | 2 | 8 | 18 | 2 |
| Ga | 31 | 2 | 8 | 18 | 3 |
| Ge | 32 | 2 | 8 | 18 | 4 |
| As | 33 | 2 | 8 | 18 | 5 |
| Se | 34 | 2 | 8 | 18 | 6 |
| Br | 35 | 2 | 8 | 18 | 7 |
| Kr | 36 | 2 | 8 | 18 | 8 |
+---------+----------+---------+---------+----------+---------+
I know all elements must have 4 orbitals due to the period (row #) of 4, and the outer most orbital (or shell), 4, is the valence.
Cr and Cu, have their valance set to 1, instead of 2, because, the electrons closer to the nucleus, requires less energy to sustain itself, and is thus more stable, but at the same time the each orbit (or shell) must have at least 1 electron on it. In regards to Cr and Cu, I thought there would be a precedence for orbit 3, the orbit preceding the valence, to be more full and within 18 or less electrons.
This forum post (link), hosted on a college's server, unfortunately fails to address the issue with Ca.