What is inside these Structure of the Atom notes
These notes follow the board textbook chapter “Structure of the Atom”. Each page has one big idea, with colour cards so you can revise fast.
- Charged particles in matter: electron and proton (4.1)
- Rutherford’s alpha-particle scattering experiment (4.2)
- Thomson’s, Rutherford’s and Bohr’s models of the atom, and the neutron (4.2)
- Distribution of electrons in shells: the 2n² rule (4.3)
- Valency (4.4)
- Atomic number, mass number, isotopes and isobars (4.5)
Also in the PDF
- Cover and chapter map: every topic with its page number, a concept diagram and what to know before you start.
- Atomic model comparison chart and electron shells K, L, M, N
- Z = p, A = p + n and the electron-shell table of the first 18 elements
- Isotopes, isobars and their uses
- Common mistakes and tips on each topic page.
- Quick-revision page: every formula and rule of the chapter on one sheet.
- Last-day checklist with answer-writing templates and a 5-minute plan.
- Practice questions with an answer key so you can check yourself.
Preview the notes
Tap the cover to see the free preview pages in the Leepie store.
Practise after you revise
Structure of the Atom: MCQs with answers
Free sample MCQs in Assamese, with an explanation for every answer. Chapter numbers on the MCQ pages follow the Leepie app and can differ from the textbook.
Practise Structure of the Atom MCQsHow to use these notes
- Read the chapter map and the “before you start” cards.
- Study one topic page at a time, then cover the worked example and solve it yourself.
- Revise from the quick-revision page every day in the last week.
- Finish with the practice questions and check your answers against the answer key.
Frequently Asked Questions
Are these revision notes free?
Chapters 1 to 3 of each Class 9 subject are free. This chapter is part of the complete General Science revision notes, with all chapters in one book (₹50): see the free preview pages in the Leepie store, then buy it. After payment the file is ready in My Library in your account.
Which language are the notes in?
The notes are written in Assamese, for students of the Assam board (SEBA / ASSEB). Chapter names also carry the English name, for example “Structure of the Atom”.
Is this an official SEBA or textbook publication?
No. Leepie’s revision notes are an independent study aid made to go with the textbook. Always read your textbook and follow your teacher’s guidance.
How should I use these notes?
Read the colour cards once, solve the worked examples yourself, then use the quick-revision page and the last-day checklist before the exam. Finish with the practice questions and check your answers.