P-Block Elements
General characteristics:
➡️ Elements belonging to groups 13 to 18 of the periodic table.
➡️ General electronic configuration of ns2np1-6.
➡️ Representative elements.
Group 15 Elements
➭ General electronic configuration: ns2np3.
➭ Elements: Nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi).
➭ Atomic and ionic radii: Increase down the group.
➭ Ionization energy: Decreases down the group.
➭ Allotropy: All elements except nitrogen show allotropy.
➭ Catenation: Nitrogen shows catenation to some extent, phosphorus shows the most, and the tendency decreases down the group.
➭ Oxidation states: +3, +5, -3.
➭ Reactivity towards hydrogen: All elements form trihydrides (MH3).
➭ Reactivity towards oxygen: All elements form trioxides (M2O3) and pentoxides (M2O5).
➭ Reactivity towards halogens: Form trihalides and pentahalides.
➭ Reactivity towards metals: React with metals to form binary compounds in -3 oxidation state.
Group 16 Elements
➭ Oxidation states: -2, +2, +4, +6.
➭ Elements: Oxygen (O), sulfur (S), selenium (Se), tellurium (Te), and polonium (Po).
➭ Ionization enthalpy: Lower than group 15 due to half-filled p-orbitals.
➭ Electron gain enthalpy: Less negative down the group due to increasing atomic size.
➭ Melting and boiling point: Increases with increasing atomic number.
➭ Reactivity with hydrogen: All elements form hydrides.
➭ Reactivity with oxygen: Form EO2 and EO3.
➭ Reactivity with halogens: Form EX2, EX4, and EX6.
Group 17 Elements
➭ Elements: Fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).
➭ Atomic and ionic radii: Smallest in their respective periods.
➭ Ionization enthalpy: Very high due to small size.
➭ Electron gain enthalpy: Maximum negative due to one electron less than stable noble gas configuration.
➭ Electronegativity: Highly electronegative, decreases down the group.
➭ Bond dissociation enthalpy: Decreases down the group due to increasing size.
➭ Colour: Coloured due to absorption of visible radiation.
➭ Oxidizing power: Strong oxidizing agents, decreases down the group.
➭ Reactivity with hydrogen: Form hydrogen halides (HX).
Group 18 Elements
➭ Elements: Helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).
➭ General electronic configuration: ns2np6 (except He: 1s2).
➭ Inertness: Due to stable noble gas configuration.
