p-Block and d-Block Elements: Most Asked Trends & Exceptions for HSC 2026

Inorganic Chemistry is often the "make or break" section for students appearing for the HSC 2026 board exams. While Physical Chemistry relies on numerical accuracy and Organic on mechanisms, the HSC Chemistry Inorganic important topics—specifically p-block, d-block, and f-block elements—require a deep understanding of periodic trends and the "rule-breaking" exceptions that examiners love to test.

If you have been struggling to memorize the vast reactions in the p-Block or the complex configurations of Transition Elements, you are not alone. For the 2026 session, the Maharashtra State Board has maintained a high weightage for these chapters, with p-Block Elements (Groups 16, 17, and 18) and Transition & Inner Transition Elements carrying 8 marks each (with options).

p-Block and d-Block Elements

Mastering the p-Block (Groups 16, 17, and 18)

The p-block is the most diverse part of the periodic table. For the 2026 exam, focus heavily on the anomalous behavior of the first elements in each group.

Anomalous Behaviour of Oxygen and Fluorine

One of the most common “Give Reason” questions.

Why do Oxygen and Fluorine behave differently from their group members?

Reason:

• Small atomic size

• High electronegativity

• Absence of vacant d-orbitals

Important Trend:

• Oxygen exists as O₂ (gas)

• Sulfur exists as S₈ (solid)

Explanation:Oxygen forms strong pπ–pπ multiple bonds, while sulfur forms single bonds and exists as a puckered ring structure.

2. Trends in Oxoacids and Halogens

You must be able to draw the structures of oxoacids of Phosphorus and Sulfur. For 2026, pay attention to:

• Interhalogen Compounds: Why are they more reactive than pure halogens? (Except Fluorine, the X-X' bond is weaker than the X-X bond).

• Boiling Points of Noble Gases: They have very low boiling points because they are monoatomic and held by weak dispersion forces (London forces).

Pro Tip for 2026: For a detailed breakdown of how to manage your time between these descriptive topics and the numerical-heavy Physical Chemistry section, check out the HSC Chemistry 2026: Complete Strategy to Score Out Of Marks on Concept Simplified.

d-Block and f-Block: The Transition Powerhouse

The d-block elements (Transition Elements) are defined by their partially filled d-subshells. This section of the HSC Chemistry Inorganic important topics is predictable if you master the following concepts:

1. Variable Oxidation States

Unlike s-block elements, transition metals show a variety of oxidation states. This is because the energy difference between (n-1)d and ns orbitals is very small, allowing electrons from both levels to participate in bond formation. Manganese ($Mn$), for example, shows the maximum number of oxidation states from +2 to +7.

2. Why are Transition Metal Ions Colored?

This is a guaranteed 2-mark question.

• Reason: The color is due to d-d transitions. When light falls on these ions, electrons from lower energy d-orbitals absorb energy and get excited to higher energy d-orbitals. The transmitted light gives the complementary color.

3. Lanthanoid Contraction

In the f-block, the steady decrease in atomic and ionic radii with increasing atomic number is known as Lanthanoid Contraction.

• Consequence: This results in the radii of the elements of the second ($4d$) and third ($5d$) transition series being nearly identical (e.g., $Zr$ and $Hf$).

High-Yield "Give Reason" Questions for 2026

To help you secure those extra marks in Section B and C of your paper, here are the most likely questions based on the 2026 pattern:

Question	Short Logic/Exception
Why is H2O a liquid but H2S a gas?	Presence of strong intermolecular Hydrogen bonding in H2O.
Why do transition metals act as good catalysts?	Ability to show variable oxidation states and provide a large surface area.
Why does Fluorine show only -1 oxidation state?	It is the most electronegative element and lacks d-orbitals to expand its octet.

For more practice on these descriptive sections, you should refer to the HSC Chemistry 2025 Question Paper with Solutions PDF. Analyzing the 2025 paper will give you a benchmark for the difficulty level of the HSC Chemistry Inorganic important topics you will face in 2026.

HSC Chemistry Inorganic Important Topics: 2026 FAQs

Q1: Which chapters have the highest weightage in Inorganic Chemistry for HSC 2026?

As per the latest 2026 blueprint, p-Block Elements and Transition and Inner Transition Elements are the highest weightage chapters in the Inorganic section, each carrying 8 marks with options. These are essential HSC Chemistry Inorganic important topics for any student aiming for 90+.

Q2: Are reactions of p-block elements mandatory for the 2026 exam?

Yes, but you should prioritize the preparation of compounds like Ammonia (Haber’s Process), Nitric Acid (Ostwald’s Process), and the structures of Oxoacids. The board often asks for balanced chemical equations.

Q3: Is the 2026 HSC Chemistry paper going to be harder than 2025?

The 2026 paper pattern follows the NEP 2020 guidelines, which emphasize conceptual understanding. Expect 25% objective questions (MCQs and VSA). If your concepts of trends and exceptions are clear, the paper will be scoring.

Q4: How can I remember the Lanthanoid series?

Use mnemonics! For example: "Lazy Cats Purr Nicely, Some Every Day, Greatly Terrible, Happy Every Time, You Look." (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu).

Conclusion

In short, mastering Inorganic Chemistry for your HSC 2026 exams isn't about rote memorization—it's about spotting the patterns and understanding why certain elements "break the rules." By focusing on the unique behaviors of elements like Oxygen and Fluorine, and getting comfortable with the colored ions and magnetic properties of the d-block, you can turn a traditionally difficult subject into your highest-scoring section.

Keep your preparation organized, focus on the "Give Reason" style of questions, and use the resources mentioned above to stay ahead of the curve. With a clear strategy, you'll find that Inorganic Chemistry is the most predictable and rewarding part of the entire paper.