Connection of shell occupancy to the periodic table

Connecting shell occupancy with row (period) number
The maximum number of electrons in each of the first three energy levels (shells) for the first twenty elements corresponds to the number of elements in rows (periods 1,2 and 3 of the periodic table.

1	2
							1H										2He
3Li	4Be											5B	6C	7N	8O	9F	10Ne
11Na	12Mg											13Al	14Si	15P	16S	17Cl	18Ar
19K	20Ca	21Sc	22Ti	23V	24Cr	25Mn	26Fe	27Co	28Ni	29Cu	30Zn	31Ga	32Ge	33As	34Se	35Br	36Kr

The first four periods (rows) of the periodic table are shown.
These contain many important elements.

Shell 1: 2 electrons	Period 1: 2 elements
Shell 2: 8 electrons	Period 2: 8 elements
Shell 3: 8 electrons	Period 3: 8 elements

In the ground (lowest energy) state for any atom, the electrons on the atom occupy the lowest energy levels (shells) available.

Elements in the same period have their outer electrons in the same shell.

Row 1 elements have either 1 or 2 electrons.

All electrons are in energy level 1 (shell 1).

Row 2 elements have between 3 and 10 electrons.

Two electrons are energy level 1 (shell 1); the rest are in energy level 2 (shell 2).

Row 3 elements have between 11 and 18 electrons.

Two electrons are in energy level l (shell 1).
Eight electrons are in energy level 2 (shell 2).
The remaining electrons are in energy level 3 (shell 3).