: 200
Most common question types: (1) Arrange elements/ions in order of IE, radius, EA, EN. (2) Identify exceptions to trends. (3) Use successive IE to identify group. (4) Isoelectronic series arrangement.
Key exceptions to memorise: IE: B < Be, O < N, Al < Mg, S < P. EA: F < Cl, N ≈ 0, noble gases ≈ 0. Radius: lanthanoid contraction (Hf ≈ Zr).
Quick checks: Isoelectronic species → rank by Z. Successive IE → count before big jump. Oxide character → left = basic, right = acidic, Al2O3 = amphoteric.
Common traps: (1) Confusing atomic radius (decreases across) with ionic radius of anions (may increase). (2) Assuming F has highest EA (it's Cl). (3) Forgetting that noble gases have highest IE in their period. (4) Mixing up periods and groups. (5) Not recognising that d-block IE trends are irregular.
Always state the electronic configuration basis for any trend explanation. JEE expects "Zeff increases" or "half-filled stability" as the reason, not just "it increases across the period."