Skip to main content
Chapter 6 of 32
Syllabus

Periodic Classification of Elements — Syllabus

NIOS · Class 10 · Science & Tech

What Periodic Classification of Elements covers in NIOS Class 10 Science & Tech: 4 topics, for the 2026-27 session.

44 questions40 flashcards4 formulas & key relations5 concepts

Interactive on Super Tutor

Studying Periodic Classification of Elements? Get the full interactive chapter.

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

Free trial, no card needed.

An illustration showing a well-organized chemist's shop with medicines classified and arranged, contrasting it with a disorganized one, to explain the need for classifying elements.
Super Tutor

One of 15 illustrations for Periodic Classification of Elements in Super Tutor — alongside flashcards, concept maps and practice questions.

4 Topics · NIOS Class 10 Science & Tech · 2026-27

Topics in Periodic Classification of Elements

1

Development of Classification of Elements

  • The first classification of elements was into metals and non-metals.
  • Germanium and antimony showed properties of both metals and non-metals, so this simple classification was limited.
  • William Prout’s 1815 work showed that the atomic mass of an element remains constant, which became a basis for classification.
2

Dobereiner’s Triads

  • In 1829, J.W. Dobereiner grouped elements into sets of three called triads.
  • The middle element of a triad had an atomic mass nearly equal to the arithmetic mean of the other two.
  • The middle element also had properties intermediate between the other two.
3

Newlands’ Law of Octaves

  • In 1864, John Alexander Newlands arranged elements in increasing order of atomic mass.
  • He observed that every eighth element had properties similar to the first.
  • This was called the Law of Octaves.
4

Mendeleev’s Periodic Law and Periodic Table

  • D’mitri Mendeleev studied 63 known elements and their compounds.
  • In 1869, he stated that the chemical and physical properties of elements are a periodic function of their atomic masses.
  • He arranged elements in increasing order of atomic mass and placed elements with similar properties in the same group.

Key Concepts

Central concept: Periodic classification of elements based on atomic mass and atomic number, showing the development from early classifications to the modern periodic table

Need for classificationEarly classificationsDobereiner's triadsNewlands' law of octavesMendeleev's periodic tableDefects of Mendeleev's tableModern periodic lawModern periodic table

Work through every topic in Periodic Classification of Elements with notes and quizzes

Start This Chapter

Frequently Asked Questions

What are the important topics in Periodic Classification of Elements for NIOS Class 10 Science & Tech?
Key topics in Periodic Classification of Elements include Development of Classification of Elements, Dobereiner’s Triads, Newlands’ Law of Octaves, Mendeleev’s Periodic Law and Periodic Table. Study these first, then practise questions on each for the NIOS Class 10 board exam.
How should I revise Periodic Classification of Elements for the NIOS Class 10 board exam?
Learn the core ideas first, then work through the 44 practice questions on Periodic Classification of Elements. Revise 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 Periodic Classification of Elements chapter — start free.

Quizzes, flashcards, an AI doubt solver and a study plan for NIOS Class 10 Science & Tech. Free to start, no card needed.