MCQs: Structure of an Atom (40 Questions)
1. Who proposed the first model of atom?
A. Dalton
B. Rutherford
C. J.J. Thomson
D. Bohr
Ans: C
2. J.J. Thomson discovered which particle?
A. Proton
B. Neutron
C. Electron
D. Nucleus
Ans: C
3. Thomson was awarded the Nobel Prize in Physics in:
A. 1897
B. 1906
C. 1908
D. 1913
Ans: B
4. According to Thomson, atom is a:
A. Hollow sphere
B. Positively charged sphere with electrons embedded
C. Negatively charged sphere
D. Solid indivisible particle
Ans: B
5. Thomson’s model is compared to:
A. Watermelon
B. Christmas pudding
C. Orange
D. Apple
Ans: B
6. In Thomson’s model, electrons are like:
A. Seeds
B. Cream
C. Dry fruits
D. Juice
Ans: C
7. According to Thomson, atom is electrically:
A. Positive
B. Negative
C. Neutral
D. Variable
Ans: C
8. Why is atom neutral according to Thomson?
A. No charge present
B. Only protons present
C. Equal positive and negative charges
D. Only electrons present
Ans: C
9. Which model could not explain later experiments?
A. Dalton
B. Thomson
C. Bohr
D. Modern
Ans: B
10. Who performed the gold foil experiment?
A. J.J. Thomson
B. Dalton
C. Ernest Rutherford
D. Chadwick
Ans: C
11. Rutherford was interested in studying:
A. Neutrons
B. Arrangement of electrons
C. Protons
D. Valency
Ans: B
12. Which particles were used in Rutherford’s experiment?
A. Beta particles
B. Gamma rays
C. Alpha particles
D. Electrons
Ans: C
13. Alpha particles are:
A. Negatively charged
B. Neutral
C. Doubly charged helium ions
D. Light particles
Ans: C
14. Gold foil was chosen because:
A. It is cheap
B. It is thick
C. It can be made very thin
D. It absorbs radiation
Ans: C
15. Thickness of gold foil was about:
A. 10 atoms
B. 100 atoms
C. 1000 atoms
D. 10,000 atoms
Ans: C
16. Most alpha particles passed through the gold foil:
A. With large deflection
B. Without deflection
C. With reflection
D. With absorption
Ans: B
17. Some alpha particles were deflected:
A. By large angles
B. By small angles
C. By 180° only
D. Not deflected
Ans: B
18. Very few alpha particles rebounded because:
A. Atom is solid
B. Atom has empty space
C. Positive charge concentrated in nucleus
D. Electrons are heavy
Ans: C
19. Rutherford concluded that most of the atom is:
A. Solid
B. Liquid
C. Empty space
D. Filled with electrons
Ans: C
20. Positive charge of atom is concentrated in:
A. Whole atom
B. Electron cloud
C. Nucleus
D. Orbits
Ans: C
21. Mass of atom mainly resides in:
A. Electrons
B. Neutrons
C. Nucleus
D. Orbits
Ans: C
22. Size of nucleus is ______ compared to atom:
A. Same
B. Larger
C. Very small
D. Infinite
Ans: C
23. Radius of nucleus is about ____ times smaller than atom:
A. 10³
B. 10⁵
C. 10⁸
D. 10¹⁰
Ans: B
24. Electrons revolve around nucleus in:
A. Random motion
B. Straight lines
C. Circular paths
D. Zig-zag paths
Ans: C
25. Rutherford proposed which model?
A. Plum pudding
B. Nuclear model
C. Atomic theory
D. Planetary law
Ans: B
26. Rutherford is known as:
A. Father of chemistry
B. Father of atom
C. Father of nuclear physics
D. Father of electrons
Ans: C
27. Rutherford was awarded Nobel Prize in:
A. Physics
B. Chemistry
C. Biology
D. Medicine
Ans: B
28. Rutherford’s experiment proved Dalton’s atom was:
A. Correct
B. Indivisible
C. Divisible
D. Solid
Ans: C
29. One drawback of Rutherford’s model is that it could not explain:
A. Mass of atom
B. Charge of atom
C. Stability of atom
D. Shape of atom
Ans: C
30. Accelerating charged particle emits:
A. Matter
B. Heat
C. Energy
D. Light only
Ans: C
31. According to classical theory, revolving electrons should:
A. Gain energy
B. Lose energy
C. Remain stable
D. Stop moving
Ans: B
32. If electrons lose energy continuously, they would:
A. Move faster
B. Escape atom
C. Fall into nucleus
D. Become neutrons
Ans: C
33. If electrons fall into nucleus, atom would become:
A. Stable
B. Highly unstable
C. Larger
D. Neutral
Ans: B
34. But atoms are actually:
A. Highly unstable
B. Rare
C. Quite stable
D. Radioactive
Ans: C
35. Which experiment disproved Thomson’s model?
A. Cathode ray experiment
B. Oil drop experiment
C. Gold foil experiment
D. Photoelectric experiment
Ans: C
36. Which particle is much heavier than electron?
A. Alpha particle
B. Beta particle
C. Electron
D. Photon
Ans: A
37. Alpha particles have mass about:
A. 1 u
B. 2 u
C. 4 u
D. 0 u
Ans: C
38. Deflection of alpha particles indicates presence of:
A. Electrons
B. Empty space
C. Positive nucleus
D. Neutrons
Ans: C
39. Number of alpha particles rebounding was:
A. Many
B. Few
C. Zero
D. Half
Ans: B
40. Rutherford’s famous quote compares rebounding to:
A. Stone hitting glass
B. Bullet hitting wall
C. Shell rebounding from tissue paper
D. Ball hitting ground
Ans: C
0 Comments