Group 13–15 Introduction

Cue Column	Note Column
What is the p-block?	Elements filling np subshells; Groups 13–18; outer config $ns^{2}$ $np^{1-6}$
Group 13 config?	$ns^{2}$ $np^{1}$ — 3 valence electrons; +3 is the main oxidation state
Group 14 config?	$ns^{2}$ $np^{2}$ — 4 valence electrons; +4 and +2 oxidation states
Group 15 config?	$ns^{2}$ $np^{3}$ — 5 valence electrons; −3 to +5 oxidation states
Why is B anomalous?	Small size, high EN, high charge density → only covalent, electron-deficient compounds; acts as Lewis acid
Key Group 13 compounds?	Diborane ( $B_{2}H_{6}$ ), Borax ( $Na_{2}B_{4}O_{7}$ · $10H_{2}O$ ), Boric acid ( $H_{3}BO_{3}$ ), $AlCl_{3}$ dimer
Key Group 14 concepts?	Diamond ( $sp^{3}$ ), Graphite ( $sp^{2}$ ), Fullerene ( $C_{60}$ ), CO toxicity, Silicon compounds
Key Group 15 concepts?	N≡N bond (945 kJ/mol), Haber process, Ostwald process, N-oxides, P-allotropes, P-oxoacids

Summary (bottom): Groups 13–15 of the p-block are among the most content-dense in NEET inorganic chemistry. The three highest-priority testable areas are: (1) Phosphorus oxoacid basicity from P-OH bond count, (2) Haber/Ostwald process conditions, and (3) Nitrogen oxide oxidation states and properties.