Atomic Structure Mcqs According to PMDC Syllabus
1. All of the following were theorized by Bohr in his description of the atom except
A. The angular momentum of electrons in multiples of h/2?
B. Electrons revolve in discrete circular orbits
C. The energy of each electron is directly proportional to n2
D. Electrons radiate energy continuously in a given orbit
Answer: Option D
2. The letters sp d and f are used to represent which quantum numbers
A. Principal
B. Azimuthal
C. Magnetic
D. Spin
Answer: Option B
3. The magnetic quantum number (QN) has its values determined directly by the value of
A. Principal (QN)
B. Azimuthal (QN)
C. Spin (QN)
D. Both a & b
Answer: Option B
4. The atomic number of an element having the maximum number of unpaired electrons in p-subshell is
A. 7
B. 10
C. 12
D. 16
Answer: Option A
5. The maximum number of electron in a subshell with? = 3fs
A. 6
B. 10
C. 14
D. 18
Answer: Option C
6. The radius of the third shell of H-atom is
A. 5.761 A?
B. 4.761 A?
C. 6.671 A?
D. 3.716 A?
Answer: Option B
7. When an atom absorbs energy the lines in the spectrum will appear which are
A. Brighter
B. Darker
C. Colourless
D. Hard to locate
Answer: Option B
8. Colour of fluorescence produced by cathode rays depends upon
A. Temperature
B. Pressure
C. Volume
D. Composition of glass
Answer: Option D
9. Which one is not true about cathode rays?
A. 9.11×10-31 Kg
B. Cast shadow
C. Heat up the platinum foil
D. Cannot ionize
Answer: Option D
10. Positive rays are produced
A. By burning of gas
B. By cooling of the gas
C. By the bombardment of cathode rays on gas molecules
D. From anode like cathode rays produced from a cathode
Answer: Option C
11. Which one is not true about cathode rays?
A. 9.11×10-31 Kg
B. Cast shadow
C. Heat up the platinum foil
D. Cannot ionize
Answer: Option D
12. Rutherford’s planet-like structure was defective and unsatisfactory because
A. Moving e- accelerate towards the nucleus
B. Continuous spectrum
C. The behaviour of electron remain unexplained
D. All Are Correct
Answer: Option D
13. The relationship between the energy of a photon of light and its frequency is given by
A. de-Broglie duel nature of matter
B. Bohrs model
C. Plancks Quantum theory
D. Rutherfords atomic model
Answer: Option C
14. Splitting of spectral lines when an atom is subjected to the magnetic field is called
A. Zeemans effect
B. Starks effect
C. Photo electric effect
D. Compton effect
Answer: Option A
15. The velocity of the photon
A. Is independent of wavelength
B. Depends upon source
C. Depends upon its frequency
D. Equals to the square of the amplitude
Answer: Option A
16. Which one of the following explain the shape of orbitals
A. Principal of quantum number
B. Azimuthal quantum number
C. Magnetic quantum number
D. Spin quantum number
Answer: Option B
17. Atom cannot be divided into simple unitstheorized by
A. Rutherford
B. Dalton
C. Bohr
D. Schrodinger
Answer: Option B
18. Pressure in gas discharge tube was kept
A. 10 torr
B. 1 torr
C. 0.1 torr
D. 0.01 torr
Answer: Option D
19. The number of fundamental particles in an atom of the lightest isotope carbon are
A. 6
B. 12
C. 18
D. 20
Answer: Option C
20. Angle of deflection was studied by
A. Hitorff
B. Stoney
C. William Crookes
D. J.Perrin
Answer: Option D
