Architecture of the Periodic Table

Understanding the coordinate system of atomic physics: Groups, Periods, and Blocks.

1. The Coordinates

Groups (Vertical)

Elements with the same number of valence electrons.

Significance: Determines chemical properties (bonding behavior).

Periods (Horizontal)

Elements with the same number of occupied electron shells (n).

Significance: Represents the filling of energy levels.

2. The Blocks

The table is divided into blocks based on the highest energy sub-level occupied by the valence electrons.

s-block
Groups 1 & 2

p-block
Groups 13–18

d-block
Groups 3–12

f-block
Lanthanoids

3. Metals vs. Non-Metals

The "Staircase Line"

Separates metals from non-metals. It runs diagonally from Boron (B) to Astatine (At). Elements touching this line are Metalloids (e.g., Si, Ge).

Left Side (Metals)	Right Side (Non-Metals)
Large atomic radii	Small atomic radii
Low Ionization Energy	High Electron Affinity
Form Cations (+)	Form Anions (−)
Basic Oxides	Acidic Oxides