Blockwise Guide to the Periodic Table: S, P, D, and F Explained

The Periodic Table is divided into blocks based on the type of atomic orbitals being filled. Each block has distinct characteristics and groups of elements.

S‑Block  

- Contains Group 1 (Alkali metals) and Group 2 (Alkaline earth metals)  

- General configuration: [Noble gas] ns^1 or [Noble gas] ns^2 

- Alkali metals (Group 1): form alkaline hydroxides when reacting with water  

- Alkaline earth metals (Group 2): form alkaline oxides and hydroxides (except Be)  

- Special case: BeO and Be(OH)2 are amphoteric, so beryllium is not included in alkaline earth metals. 

P‑Block  

- Contains metals, non‑metals, metalloids, and noble gases  

- Groups 13 to 18  

- General configuration: [Noble gas] ns^2 np^{1–6}  

Subgroups:  

- Pnictogens (Group 15): N, P, As, Sb, Bi --> many are poisonous  

- Chalcogens (Group 16): O, S, Se, Te, Po --> ore‑forming elements  

- Halogens (Group 17): F, Cl, Br, I, At --> salt‑forming elements  

- Noble gases (Group 18): He, Ne, Ar, Kr, Xe --> least reactive  

D‑Block  

- All metals, Groups 3 to 12  

- General configuration: [Noble gas] ns^{1–2} (n-1)d^{1–10} 

- All d‑block metals except Group 12 (Zn, Cd, Hg) are transition elements  

- Transition metals form a bridge between reactive s‑block metals and less reactive p‑block elements  

- They have partially filled d‑subshells in atoms or ions  

F‑Block  

- All metals, part of Group 3  

- Atomic numbers 58–71: Lanthanides  

- Atomic numbers 90–103: Actinides  

- General configuration: [Noble gas] ns^2 (n-1)d^{0–2} (n-2)f^{1–14}  

- Known as inner transition elements 

- Lanthanides: 14 elements after lanthanum  

- Actinides: 14 elements after actinium