Now lets have a look at class 9 Chapter 8 Journey Inside the Atom, a chemistry chapter. Here we have 35 MCQs and additional 10 true & false and 10 fill in the blanks questions.
Lets have a look at some of the top points for this chapter –
- Ancient thinkers proposed indivisible particles of matter.
- Dalton introduced the first scientific atomic theory.
- Radioactivity proved atoms contain smaller particles.
- Thomson discovered negatively charged electrons.
- Thomson proposed the plum pudding atomic model.
- Rutherford’s gold foil experiment discovered the nucleus.
- Most of an atom is empty space.
- Protons carry positive charge inside the nucleus.
- Bohr proposed fixed energy levels for electrons.
- Neutrons were discovered by James Chadwick.
- Atomic number equals the number of protons.
- Mass number equals protons plus neutrons.
- Electrons fill shells following Bohr-Bury rules.
- Electronic configuration shows electron distribution in shells.
- Valency depends on valence electrons and octet completion.
35 MCQ Questions for Class 9 Science: Chapter 8 Journey Inside the Atom
Question 1. Who proposed the concept of parmanus?
a) Dalton
b) Rutherford
c) Acharya Kanada
d) Chadwick
Answer:
c) Acharya Kanada — Ancient Indian atomic concept.
Question 2. What does ‘atomos’ mean?
a) Charged particle
b) Divisible
c) Indivisible
d) Neutral particle
Answer:
c) Indivisible — Greek origin of atom.
Question 3. Who proposed the first scientific atomic theory?
a) Bohr
b) Dalton
c) Thomson
d) Rutherford
Answer:
b) Dalton — Based on experiments.
Question 4. Which discovery proved atoms are divisible?
a) Molecules
b) Radioactivity
c) Compounds
d) Diffusion
Answer:
b) Radioactivity — Revealed subatomic particles.
Question 5. Who discovered the electron?
a) Chadwick
b) Bohr
c) Thomson
d) Rutherford
Answer:
c) Thomson — Cathode ray experiments.
Question 6. Electrons carry which charge?
a) Positive
b) Neutral
c) Negative
d) Variable
Answer:
c) Negative — Fundamental negative particle.
Question 7. Thomson’s model is called:
a) Nuclear model
b) Quantum model
c) Plum pudding model
d) Planetary model
Answer:
c) Plum pudding model — Electrons embedded throughout.
Question 8. Which experiment tested Thomson’s model?
a) Oil drop experiment
b) Gold foil experiment
c) Diffusion experiment
d) Flame test
Answer:
b) Gold foil experiment — Alpha scattering study.
Question 9. Alpha particles are:
a) Negatively charged
b) Neutral
c) Positively charged
d) Uncharged atoms
Answer:
c) Positively charged — Used by Rutherford.
Question 10. Most alpha particles passed through gold foil because:
a) Nucleus is large
b) Atom is empty space
c) Electrons repel them
d) Gold is soft
Answer:
b) Atom is empty space — Rutherford’s conclusion.
Question 11. Rutherford discovered the:
a) Electron
b) Neutron
c) Nucleus
d) Molecule
Answer:
c) Nucleus — Dense central region.
Question 12. Rutherford’s model is also called:
a) Plum pudding model
b) Quantum model
c) Planetary model
d) Wave model
Answer:
c) Planetary model — Electrons orbit nucleus.
Question 13. Rutherford’s model failed to explain:
a) Atomic mass
b) Stability of atom
c) Electrons
d) Radioactivity
Answer:
b) Stability of atom — Orbiting electrons issue.
Question 14. Protons are found in the:
a) Shells
b) Orbit
c) Nucleus
d) Vacuum
Answer:
c) Nucleus — Positive charge source.
Question 15. Proton charge is:
a) -1
b) 0
c) +1
d) +2
Answer:
c) +1 — Opposite electron charge.
Question 16. Who proposed fixed energy levels?
a) Dalton
b) Bohr
c) Chadwick
d) Thomson
Answer:
b) Bohr — Explained atomic stability.
Question 17. Closest shell to nucleus is:
a) L
b) M
c) N
d) K
Answer:
d) K — Lowest energy level.
Question 18. Energy increases from:
a) Outer to inner shell
b) Nucleus outward
c) Randomly
d) Constantly
Answer:
b) Nucleus outward — Higher shells, higher energy.
Question 19. Electrons move between shells by:
a) Changing mass
b) Absorbing or releasing energy
c) Splitting atoms
d) Losing charge
Answer:
b) Absorbing or releasing energy — Fixed amounts.
Question 20. Who discovered the neutron?
a) Rutherford
b) Bohr
c) Chadwick
d) Thomson
Answer:
c) Chadwick — Solved mass puzzle.
Question 21. Neutron charge is:
a) +1
b) -1
c) +2
d) 0
Answer:
d) 0 — Electrically neutral.
Question 22. Atomic mass mainly comes from:
a) Electrons
b) Protons and neutrons
c) Shells
d) Energy levels
Answer:
b) Protons and neutrons — Nucleus contributes mass.
Question 23. Symbol of iron is:
a) Ir
b) Fe
c) In
d) Fi
Answer:
b) Fe — From Latin ferrum.
Question 24. Symbol of sodium is:
a) So
b) Sd
c) Na
d) S
Answer:
c) Na — From Natrium.
Question 25. Atomic number is represented by:
a) A
b) Z
c) N
d) P
Answer:
b) Z — Number of protons.
Question 26. Atomic number equals number of:
a) Neutrons
b) Nucleons
c) Protons
d) Shells
Answer:
c) Protons — Element identity.
Question 27. Mass number is represented by:
a) Z
b) A
c) N
d) E
Answer:
b) A — Protons plus neutrons.
Question 28. Nucleons are:
a) Electrons and protons
b) Protons and neutrons
c) Electrons only
d) Shell particles
Answer:
b) Protons and neutrons — Nuclear particles.
Question 29. Maximum electrons in K-shell:
a) 8
b) 18
c) 2
d) 32
Answer:
c) 2 — Using 2n² rule.
Question 30. Maximum electrons in L-shell:
a) 2
b) 8
c) 18
d) 32
Answer:
b) 8 — 2 × 2².
Question 31. Electronic configuration means:
a) Atomic mass
b) Electron distribution in shells
c) Proton arrangement
d) Nuclear structure
Answer:
b) Electron distribution in shells — Shell-wise arrangement.
Question 32. Outermost shell is called:
a) K-shell
b) Core shell
c) Valence shell
d) Nuclear shell
Answer:
c) Valence shell — Determines reactivity.
Question 33. Electrons in valence shell are called:
a) Core electrons
b) Valence electrons
c) Free electrons
d) Orbit electrons
Answer:
b) Valence electrons — Outer shell electrons.
Question 34. A complete valence shell usually contains:
a) 2 electrons
b) 4 electrons
c) 6 electrons
d) 8 electrons
Answer:
d) 8 electrons — Stable octet.
Question 35. Valency is the number of electrons:
a) Created
b) Destroyed
c) Gained, lost or shared
d) Stored
Answer:
c) Gained, lost or shared — To complete octet.
10 True and False Questions for Chapter 8 Journey Inside the Atom
Question 1. Dalton considered atoms indivisible particles. (True/False)
Answer:
True
Question 2. Electrons carry a positive charge. (True/False)
Answer:
False
Question 3. Thomson discovered the electron using cathode rays. (True/False)
Answer:
True
Question 4. Rutherford concluded that atoms are mostly empty space. (True/False)
Answer:
True
Question 5. The nucleus contains most of the atom’s mass. (True/False)
Answer:
True
Question 6. Neutrons have the same charge as protons. (True/False)
Answer:
False
Question 7. Bohr proposed fixed energy levels for electrons. (True/False)
Answer:
True
Question 8. Atomic number is equal to the number of neutrons. (True/False)
Answer:
False
Question 9. Valence electrons are present in the outermost shell. (True/False)
Answer:
True
Question 10. An atom with a complete octet is generally stable. (True/False)
Answer:
True
10 Fill in the Blanks Questions for Chapter 8 Journey Inside the Atom
Question 1. The scientist who discovered the electron was __________.
Answer:
J. J. Thomson
Question 2. Rutherford’s experiment used a thin __________ foil.
Answer:
Gold
Question 3. The positively charged center of an atom is called the __________.
Answer:
Nucleus
Question 4. Electrons revolve around the nucleus in fixed __________.
Answer:
Shells
Question 5. The particle with no electric charge is the __________.
Answer:
Neutron
Question 6. The number of protons in an atom is its __________ number.
Answer:
Atomic
Question 7. The sum of protons and neutrons gives the __________ number.
Answer:
Mass
Question 8. The outermost shell of an atom is called the __________ shell.
Answer:
Valence
Question 9. The maximum number of electrons in the K-shell is __________.
Answer:
2
Question 10. Valency is related to electrons in the __________ shell.
Answer:
Valence
Question on Match the Columns
Unmatched Columns – Questions
| Column A | Column B |
|---|---|
| (i) J. J. Thomson | (a) Fixed energy levels for electrons |
| (ii) Rutherford | (b) Discovered neutron |
| (iii) Bohr | (c) Discovered electron |
| (iv) Chadwick | (d) Number of protons |
| (v) Atomic Number | (e) Gold foil experiment |
| (vi) Mass Number | (f) Sum of protons and neutrons |
Matched Columns – Answer
| Column A | Column B |
|---|---|
| (i) J. J. Thomson | (c) Discovered electron |
| (ii) Rutherford | (e) Gold foil experiment |
| (iii) Bohr | (a) Fixed energy levels for electrons |
| (iv) Chadwick | (b) Discovered neutron |
| (v) Atomic Number | (d) Number of protons |
| (vi) Mass Number | (f) Sum of protons and neutrons |
Related Class 9 Chemistry Chapters
Atomic structure links back to matter and forward to reactions:
- Atomic Foundations of Matter MCQs – atomic mass, moles and formulas.
- Exploring Mixtures and their Separation MCQs – pure substances vs mixtures.
- Exploration: World of Secondary Science MCQs – how atomic models were built.
Next chapter: Chapter 9 – Atomic Foundations of Matter
See all chapters: MCQ Questions for Class 9 Science – All 13 Chapters
