Class 9
Science
Chapter 8
Exploration (latest NCERT)
Journey Inside the Atom
Free NCERT practice questions for Class 9 Science, Chapter 8 — 85 questions across MCQs, short-answer, long-answer, numericals and more. Download a printable PDF worksheet in seconds. No signup, no ads, no paywall.
What this chapter covers
Class 9 Science Chapter 8 'Journey Inside the Atom' from NCERT Exploration walks through atomic structure. Students follow the discovery of electrons, protons and neutrons, study Thomson's and Rutherford's models, and reach the Bohr model. Atomic number, mass number, isotopes and isobars are defined; electron-shell filling and valency are explained for the first 20 elements.
Key topics in this chapter
- Discovery of electron, proton, neutron
- Thomson, Rutherford and Bohr models
- Atomic number and mass number
- Isotopes and isobars
- Electron-shell filling and valency
Sample questions from this chapter
Here are 6 real questions students will encounter when they generate a worksheet for this chapter. Every question includes the answer.
MCQ
Medium
1 mark
Who discovered the neutron?
(a) Thomson
(b) Rutherford
(c) Bohr
(d) James Chadwick
Answer: James Chadwick
Short Answer
Medium
3 marks
State two postulates of Bohr's model of the atom.
Answer: • Electrons revolve around the nucleus in fixed energy levels (shells).
• While in a shell, an electron does not lose energy.
Fill in the Blank
Easy
1 mark
Atoms are the building __________ of matter.
Answer: blocks
Numerical
Medium
2 marks
An atom ⁷⁰X has 31 electrons. How many neutrons are in its nucleus?
Answer: • Electrons = protons = 31.
• Mass number = 70.
• Neutrons = 70 − 31 = 39.
Very Short
Medium
1 mark
What did J. J. Thomson propose about the atom?
Answer: Electrons are embedded in a positively charged sphere (plum pudding model).
True / False
Medium
1 mark
State True or False: Isotopes have the same mass number.
Answer: False. Isotopes have the same atomic number but different mass numbers.
Generate a worksheet with all 85 questions →
Frequently asked questions
What is included in Class 9 Science Chapter 8 (Journey Inside the Atom)?
This chapter has 85 NCERT-aligned practice questions covering all the concepts from the Exploration textbook's Chapter 8. Questions span easy, medium and hard levels across 10 different formats so students get a balanced practice set.
Are these questions based on the new NCERT Exploration textbook?
Yes. Every question on Practico for Class 9 Science is mapped directly to the latest NCERT Exploration textbook (the one CBSE schools are using now). The chapter numbers and chapter titles match the textbook exactly.
How many questions can I practice from this chapter?
85 questions are available right now. You can pick how many you want at a time — generate 10 quick MCQs, a 30-question worksheet, or a full exam-style mix. Each generation gives you a different random set.
Can I download a free PDF worksheet for Journey Inside the Atom?
Yes — completely free, no sign-up required. Pick this chapter, choose the number of questions and types you want, and download a printable PDF (with or without answers) in one click.
What question types are available?
This chapter has assertion reason, fill blank, image, long, match, mcq, numerical, short, true false, very short. You can mix any combination, or filter to just the type you want to practice — for example, only numericals to drill calculation, or only short-answer questions for exam revision.
Is Practico aligned with CBSE exam patterns?
Yes. Practico questions are tagged by marks (1, 2, 3, 5) and by difficulty (Easy/Medium/Hard) just like CBSE exam blueprints, so you can build a worksheet that mirrors a real unit test or annual exam.