PYQ Analysis — Previous Year Question Patterns — Notes

Frequency Map (NEET 2010–2024)

Topic Tested	Frequency	Typical Format
Isoelectronic ionic radii order	Very High (yearly)	Arrange $N^{3-}$ , $O^{2-}$ , $F^{-}$ , $Na^{+}$ , $Mg^{2+}$ , $Al^{3+}$ in increasing/decreasing order
IE exception: Be > B, N > O	High (alternate years)	"Which of the following has higher 1st IE?"
EGE: Cl vs F anomaly	High	"Which halogen has most negative EGE?"
Block classification	Moderate	"Which block does element X belong to?"
Diagonal relationships	Low–Moderate	"Which pair shows diagonal relationship?"
Electronegativity trend	Moderate	"Arrange elements in decreasing EN order"
Anomalous behavior of first-group element	Low	"Why does N show anomalous behavior?"

NEET-Style High-Value Questions

PYQ Type 1: The correct order of ionic radii of $\text{C}^{4-},\,\text{N}^{3-},\,\text{O}^{2-},\,\text{F}^-$ is: → $\text{C}^{4-} > \text{N}^{3-} > \text{O}^{2-} > \text{F}^-$ (all have 10 electrons; fewer protons = larger)

PYQ Type 2: $IE_{1}$ of Be is greater than B because: → Be has filled 2 $s^{2}$ subshell (extra stability); B has one electron in 2p (easier removal)

PYQ Type 3: Element with highest electron gain enthalpy: → Chlorine (not fluorine) — EGE(Cl) = −349 kJ/mol

PYQ Type 4: Diagonal relationship between Be and Al is shown by: → Both have amphoteric oxides; both form covalent chlorides; both dissolve in NaOH; max covalency = 4