Skip to main content
Super TutorResources
Chapter 3 of 32
QuestionsNotesFlashcardsSummaryFormulasQuizConceptsSyllabusPlan
Revision Notes

Atoms and Molecules

NIOS · Class 10 · Science & Tech

Quick revision notes for Atoms and Molecules — NIOS Class 10 Science & Tech. Key concepts, formulas, and definitions for last-minute revision.

93 questions42 flashcards5 concepts

Interactive on Super Tutor

Studying Atoms and Molecules? Get the full interactive chapter.

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

Try Super Tutor — Free

1,000+ Class 10 students started this chapter today

An infographic comparing the ancient Indian (Maharishi Kanad, Pakudha Katyayan) and Greek (Democritus, Leucippus) philosophical ideas about the divisibility of matter and the concept of 'Parmanu' and
Super Tutor

Learn better with visuals Super Tutor has hundreds of illustrations like this across every chapter — all free to try.

Get started

Key Topics to Revise

1

1. Laws of Chemical Combination

  • The law of conservation of mass states that in every chemical reaction, total mass of reactants is equal to total mass of products.
  • Lavoisier proved this law using a chemical balance in an experiment involving mercury and oxygen.
  • When mercury was heated in air, mercury (II) oxide formed and the gas left behind did not support combustion or life; it was nitrogen.
2

2. Dalton’s Atomic Theory and Atom

  • John Dalton arranged earlier atomic ideas into a scientific theory and published it in 1803.
  • Dalton's atomic theory explained the laws of conservation of mass and constant proportions.
  • Dalton’s first postulate states that matter consists of indivisible atoms.
3

3. Size, Mass, Atomic Number, and Isotopes

  • Atoms are extremely small and cannot be seen with the naked eye.
  • Nanometer is used to express atomic size, and 1 nm = 10^-9 m.
  • One teaspoon of water contains about three times as many atoms as the Atlantic ocean contains teaspoons of water.
4

4. Molecule, Molecular Mass, and Formula Mass

  • A molecule is the smallest particle of an element or compound that can exist freely under ordinary conditions.
  • A molecule is an aggregate of two or more atoms held together by chemical bonds.
  • Oxygen molecule O2 is diatomic.

Get complete notes with diagrams and examples

Full Notes

Key Concepts

Ancient Indian and Greek thinkers proposedIn a chemical reactionA pure compound always containsDalton arranged earlier atomic ideas intoWhen two elements form more than

Frequently Asked Questions

What are the important topics in Atoms and Molecules for NIOS Class 10 Science & Tech?
Key topics in Atoms and Molecules include Atoms and Molecules Concept Map, Atoms and Molecules - Chapter Overview, Atoms and Molecules - Complete Chapter Overview. These are the concepts NIOS Class 10 examiners draw on most — study them first, then practise related questions.
How to score full marks in Atoms and Molecules — NIOS Class 10 Science & Tech?
Understand the core concepts first, then work through the 93 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.

More resources for Atoms and Molecules

All 32 chapters — NIOS Class 10 Science & Tech Revision Notes

For serious students

Get the full Atoms and Molecules chapter — for free.

Quizzes, flashcards, AI doubt-solver and a step-by-step study plan for NIOS Class 10 Science & Tech.

Try Super Tutor Free
Try the full chapter — Free