Skip to main content
Chapter 3 of 15
Revision Notes

p-Block Elements-I

Tamil Nadu Board · Class 12 · Chemistry

Quick revision notes for p-Block Elements-I — Tamil Nadu Board Class 12 Chemistry. Key concepts, formulas, and definitions for last-minute revision.

44 questions30 flashcards5 concepts

Interactive on Super Tutor

Studying p-Block Elements-I? Get the full interactive chapter.

Quizzes, flashcards, AI doubt-solver and a step-by-step study plan — built for revision notes and more.

1,000+ Class 12 students started this chapter today

Key Topics to Revise

1

General Trends in p-Block Elements

  • General electronic configuration: ns², np¹⁻⁶ (n = 2 to 6)
  • Each group has similar outer shell configuration; elements differ only in the value of 'n'
  • Group 18 (ns²np⁶) has completely filled p orbitals — most stable, least reactive, hence called inert gases
2

Anomalous Behaviour of First Elements of p-Block Groups

  • First member of EACH p-block group differs significantly from remaining members of the group
  • Three main reasons: (i) Small size, (ii) High IE and high electronegativity, (iii) Absence of d-orbitals in valence shell
  • Boron (Group 13): metalloid, not metal like Al, Ga, In, Tl. Shows diagonal relationship with Silicon
3

Group 13 — Boron Family: Occurrence, Physical and Chemical Properties

  • Boron occurs as borates: Borax — Na₂[B₄O₅(OH)₄]·8H₂O and Kernite — Na₂[B₄O₅(OH)₄]·2H₂O
  • Aluminium is the MOST ABUNDANT METAL in Earth's crust; chief ore: Bauxite (Al₂O₃·2H₂O)
  • Ga, In, Tl occur as sulphides and in trace amounts
4

Borax [Na₂B₄O₇·10H₂O] — Preparation, Properties and Uses

  • Borax = sodium salt of tetraboric acid
  • Actual formula contains tetranuclear units [B₄O₅(OH)₄]²⁻ — known as prismatic form
  • Three forms: Prismatic borax (Na₂B₄O₇·10H₂O), Jeweller's/Octahedral borax (Na₂B₄O₇·5H₂O), Borax glass (Na₂B₄O₇)

Get complete notes with diagrams and examples

Full Notes

Key Concepts

pThe maximum oxidation state (group oxidationGenerallyIn Group 13Metallic character increases down a group

Frequently Asked Questions

What are the important topics in p-Block Elements-I for Tamil Nadu Board Class 12 Chemistry?
Key topics in p-Block Elements-I include Overview of p-block elements classification and key characteristics, Relationship between group number and electronic configuration for p-block elements, Trend of metallic character and ionisation enthalpy in p-block elements. These are the concepts Tamil Nadu Board Class 12 examiners draw on most — study them first, then practise related questions.
How to score full marks in p-Block Elements-I — Tamil Nadu Board Class 12 Chemistry?
Understand the core concepts first, then work through the 44 practice questions available for this chapter. Revise formulas and definitions regularly, and use flashcards for quick recall before the exam.

Sources & Official References

Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.

For serious students

Get the full p-Block Elements-I chapter — for free.

Quizzes, flashcards, AI doubt-solver and a step-by-step study plan for Tamil Nadu Board Class 12 Chemistry.