Electronic Configuration and General Properties — Predicted 2026

AI-Predicted Question Angles for UPSC 2026

Based on trend analysis, current affairs, and recurring themes in Electronic Configuration and General Properties.

Comparative stability of +1 and +3 oxidation states for In and Tl.

high

The inert pair effect is a hallmark property of heavier p-block elements, and its impact on oxidation state stability is a fundamental concept. NEET frequently tests the application of this effect, especially for Indium and Thallium, where the +1 state becomes increasingly stable. Questions might ask to compare the stability of $InCl$ vs $InCl_3$ or $TlCl$ vs $TlCl_3$, or to identify the most stable oxidation state for a given element.

Ordering of first ionization enthalpies for Group 13 elements, including reasons for anomalies.

high

The irregular trend in ionization enthalpies (B > Al < Ga > In < Tl) is a direct consequence of d-block and lanthanide contractions and poor shielding. This is a classic NEET question type that assesses a student's understanding of these complex electronic effects. Questions could ask for the correct order or to explain why $IE_1(Ga) > IE_1(Al)$ or $IE_1(Tl) > IE_1(In)$.

Impact of d-block contraction on atomic radii and other properties.

medium

The d-block contraction, specifically the smaller atomic radius of Gallium compared to Aluminium, is a critical anomaly. Questions might directly ask about this comparison, its cause, or how it influences other properties like electronegativity or density. Understanding the poor shielding of d-electrons is key here.

Nature of Boron (non-metal) vs. other Group 13 elements (metals).

medium

The transition from non-metallic to metallic character down the group is a general trend, but Boron's distinct non-metallic nature is often highlighted. Questions might ask to identify the non-metallic element in Group 13 or to compare the bonding nature (covalent vs. ionic) of Boron compounds with those of Aluminium.