Chemistry For Class IX (New Book ) - Chapter No. 2- Atomic Structure - Multiple Choice Questions And Fill In The Blanks

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Chapter No.2 - Atomic Structure
MCQs And Fill In The Blanks
Text Book Exercise

SECTION- A: MULTIPLE CHOICE QUESTIONS
Tick Mark (✓) the correct answer

1. In an atom number of protons and neutrons are added to obtain:
(a) number of electrons
(b) number of nucleons ✓
(c) atomic number of element
(d) number of isotopes

2. If proton number is 19, electron configuration will be:
(a) 2, 8, 9
(b) 2, 8, 8, 1 ✓
(c) 2, 8, 1
(d) 2, 8, 3

3. If nucleon number of potassium is 39, number of neutrons will be:
(a) 39
(b) 19
(c) 20 ✓
(d) 29

4. The isotope C-12 is present in abundance of:
(a) 96.9%
(b) 97.6%
(c) 98.8% ✓
(d) 99.7%

5. Electronic configuration is distribution of:
(a) proton
(b) neutron
(c) electron ✓
(d) positron

6. Which one of the following is most penetrating?
(a) electron
(b) Proton
(c) alpha particle
(d) neutron ✓

7. How many sub-shells in a L shell:
(a) one
(b) two ✓
(c) three
(d) four

8. De Brog extend the wave particle duality to electron in:
(a) 1920
(b) 1922
(c) 1923 ✓
(d) 1925

9. Name the material of screen which used in Rutherford atomic model:
(a) Aluminum foil
(b) Zinc sulphide ✓
(c) Sodium sulphide
(d) Aluminum sulphide

10. Which rays are used for sterilization of medical instruments:
(a) α-rays
(b) β-rays
(c) γ-rays ✓
(d) x-rays

11. The word atom is derived from a Greek word ATOMOS means:
(a) unbreakable ✓
(b) indivisible
(c) inconsequential
(d) insignificant

12. The word atom is derived from a word ATOMOS, which was first described by Greek philosopher:
(a) Socrates
(b) Aristotle
(c) Plato
(d) Democritus ✓

13. Democritus belief that all matter consists of very small indivisible particles which are known as:
(a) atoms ✓
(b) molecules
(c) ions
(d) electrons

14. This English chemist suggested the fundamental atomic theory.
(a) J.J. Thomson
(b) John Dalton ✓
(c) William Crooks
(d) M. Faraday

15. The first subatomic particle, electron, was discovered by:
(a) M. Faraday & Chadwick
(b). J. J. Thomson & Rutherford
(c) M. Faraday, J.J. Thomson & Chadwick
(d) M. Faraday, William Crooks & J.J. Thomson ✓

16. Goldstein and Ernest Rutherford identified the subatomic particle:
(a) electron
(b) proton ✓
(c) neutron
(d) nucleus

17. The third subatomic particle, neutron, was revealed by:
(a) J.J. Thomson
(b) William Crooks
(c) Chadwick ✓
(d) Rutherford

18. Which particle is the lightest in the following?
(a) Electron ✓
(b) Proton
(c) Neutron
(d) 𝛼-particles

19. It was discovered in discharge tube experiment.
(a) 𝛼-particles
(b) Neutron
(c) Proton
(d) Electron ✓

20. Cathode rays consist of fast moving:
(a) atoms
(b) electrons ✓
(c) protons
(d) neutrons

21. In discharge tube, cathode rays travel in straight line from:
(a) cathode towards anode ✓
(b) anode towards cathode
(c) cathode to all directions
(d) anode to all directions

22. Which one of the following has a negative charge?
(a) Neutrons
(b) Protons
(c) Electrons ✓
(d) Nucleus

23. The charge and mass ratio (e/m) of cathode particles (or electrons) is:
(a) 1.7588 x 10⁸ coulomb per gram ✓
(b) 6.63 x 10^-34 JS
(c) 9.11 x 10^-26 coulomb per gram
(d) 1.67 x 10^-25 JS

24. Cathode rays (or electrons) can produce mechanical pressure indicating they possess:
(a) mass
(b) charge
(c) potential energy
(d) kinetic energy ✓

25. Which one of the following particles has positive charge?
(a) Neutrons
(b) Protons ✓
(c) Electrons
(d) Nucleus 

26. Goldstein justify that atoms are electrically:
(a) positive
(b) negative
(c) neutral ✓
(d) None of these

27. In discharge tube, canal rays (or protons) travel in straight line from:
(a) cathode towards anode
(b) anode towards cathode ✓
(c) cathode to all directions
(d) anode to all directions

28. The charge and mass ratio (e/m) of protons is:
(a) is much smaller than an electron bob ✓
(b) is much greater than electron
(c) is equal to the e/m ratio of electron
(d) None of these

29. The mass of a proton is 1836 times more than the mass of:
(a) atom
(b) neutron
(c) 𝛼-particle
(d) electron ✓

30. In 1932, he become successful to discover Neutron.
(a) Goldstein
(b) J.J. Thomson
(c) Rutherford
(d) Chadwick ✓

31. The neutrons have:
(a) negative charge
(b) positive charge
(c) no charge ✓
(d) None of them

32. The mass of a neutron is almost equal to that of:
(a) protrons ✓
(b) electron
(c) nucleus
(d) All of them

33. These particles are most penetrating in matter.
(a) proton
(b) neutrons ✓
(c) electrons
(d) atoms

34. All atoms can be identified by their:
(a) number of protons they contain ✓
(b) number of neutrons they contain
(c) number of electrons they contain
(d) atomic shells

35. The number of protons in the nucleus of an atom is called:
(a) atomic mass
(b) atomic weight
(c) atomic charge
(d) atomic number ✓

36. Atomic number represented by:
(a) N
(b) NA
(c) Z ✓
(d) None of these

37. The elements are identify by their:
(a) atomic weight
(b) atomic number ✓
(c) atomic mass
(d) valency

38. Different elements have different atomic numbers because of different number of:
(a) protons ✓
(b) electrons
(c) neutrons
(d) shells

39. Atomic number of Carbon (C) is 6. Each carbon atom has:
(a) 3 protons & 3 neutrons
(b) 3 protons & 3 electrons
(c) 6 protons & 6 neutrons
(d) 6 protons & 6 electrons ✓

40. The total sum of proton and neutrons in the nucleus of an atom is called:
(a) atomic weight
(b) atomic number
(c) mass number ✓
(d) valency

41. Mass number represented by:
(a) N
(b) NA
(c) Z
(d) A ✓

42. The sodium (Na) atom has Z = 11 and mass number A= 23. It has:
(a) 11 protons and 12 neutrons ✓
(b) 11 protons and 23 neutrons
(c) 23 protons and 11 neutrons
(d) 12 protons and 11 neutrons

43. Uranium, Radium and Polonium are:
(a) metals
(b) non-metals
(c) radioactive elements ✓
(d) gases

44. An atom consist of a positively charged, dense and very small nucleus containing protons and neutron. The entire mass is concentrated in the nucleus of an atom. It is a postulate of:
(a) Rutherford Atomic Model ✓
(b) Bohr's Atomic Model
(c) Modern Atomic Model
(d) None of them

45. The electrons are revolving around the nucleus in circular paths. These circular paths are known as:
(a) orbits
(b) shells
(c) Both 'a' & 'b' ✓
(d) None of them

46. The energy levels are represented by an integer (n = 1, 2, 3....) known as:
(a) Avogadro's number
(b) atomic number
(c) mass number
(d) quantum number ✓

47. The emission or absorption is discontinuous in the form of an energy packet called:
(a) quantum
(b) photon
(c) Both 'a' & 'b' ✓
(d) None of these

48. In 1900, quantum theory was presented by:
(a) Neil Bohr
(b) Max Planck ✓
(c) Louis De Broglie
(d) Schrodinger

49. He proposed a relationship between mass and energy to explain the photoelectric effect by wave-particle duality as E = mc².
(a) Louis De Broglie
(b) Albert Einstein ✓
(c) Schrodinger
(d) Max Planck

50. He proposed a hypothesis that all matter has particle as well as wave nature at the submicroscopic level.
(a) Louis De Broglie ✓
(b) Albert Einstein
(c) Schrodinger
(d) Max Planck

51. M shell has:
(a) 1 subshell
(b) 2 subshells
(c) 3 subshells ✓
(d) 4 subshells

52. The maximum number of electrons that can be accommodated in a shell is represented by the formula:
(a) 2n
(b) 2n² ✓
(c) 2n³
(d) 2n⁴

53. The electronic configuration of oxygen is:
(a) 1s² 2s² 2p¹
(b) 1s² 2s² 2p²
(c) 1s² 2s² 2p³
(d) 1s² 2s² 2p⁴ ✓

54. Electronic configuration of sodium is:
(a) 1s² 2s² 2p⁶ 3s² 3p²
(b) 1s² 2s² 2p⁶ 3s² 3p¹  ✓
(c) 1s² 2s² 2p² 3s²
(d) 1s² 2s² 2p⁶ 3s¹

55. Isotopes are atoms of the same element having the:
(a) same atomic number but the different mass number ✓
(b) same atomic number and mass number
(c) same mass number but different atomic number
(d) Both 'a' & 'b'

56. Isotopes have the:
(a) same number of neutrons but different number of electrons
(b) same number of neutrons but different number of protons
(c) same number of protons but the different number of neutrons ✓
(d) Both 'a' & 'b"

57. Isotopes have the:
(a) same physical properties but different chemical properties
(b) same chemical properties but different physical properties ✓
(c) same chemical and physical properties
(d) None of them

58. Hydrogen has:
(a) two isotopes
(b) three isotopes ✓
(c) four isotopes
(d) No isotopes

59. Carbon 13 possess:
(a) 6 protons and 7 neutrons ✓
(b) 6 protons and 6 neutrons
(c) 7 protons and 7 neutrons
(d) 7 protons and 7 electrons

60. Chlorine has:
(a) two isotopes ✓
(b) three isotopes
(c) four isotopes
(d) No isotopes

61. Number of protons + Number of neutrons of an element is:
(a) atomic number
(b) formula number
(c) mass number ✓
(d) isotopes


62. A-Z indicates the number of:
(a) electrons
(b) protons
(c) neutrons ✓
(d) 𝛼-particles

Fill In The Blanks:

1. The Electron is lightest particle carrying a negative charge in an Atom discovered by J.J.Thomson and William Crooks.
2. The Proton is positively charge particle discovered by Goldstein in 1886.
3. J.J.Thomson investigate properties of proton in 1897.
4. In 1932 Chadwick become successful to discover Neutron.
5. Lord Rutherford in 1911, carried out series of experiments and proposed a new model for the atom
6. Lord Rutherford in 1911, discovered that an atom contains nucleus at the center and electrons revolve around this nucleus.
7. In 1913 Neil Bohr proposed another atomic model to remove or replaced the Rutherford atomic model.
8. In 1913 Neil Bohr explained the line spectrum of Hydrogen atom based on quantum theory of Max Planck.
9. In 1923 Lois De Broglie extend the wave particle duality to electron.
10. In 1923 Lois De Broglie proposed a hypothesis that all matter has particle as well as wave nature at the sub microscopic level.
11. The Energy levels or Shell or Orbital are all possible paths on which electrons are revolving around nucleus.
12. The Energy levels or Shell or Orbital are shows by 'n'.
13. The Energy levels or Shell or Orbital are named as K, L, M, N, O, P.
14. Main energy level are divided in to sub energy levels and known as sub shells.
15. The distribution of electrons among the different orbits/shells and sub shells is known as the electronic configuration of an atom.
16. Atoms of the same elements having same atomic number but different atomic masses are called isotopes.
17. Isotopes have same number of electron and same number of protons, but different number of neutrons.
18. The Isotopes are used in research laboratories, medical centers, industrial facilities, food irradiation plants and many consumer products.