JEE Physics Atoms MCQs Set B

Question: The energy of hydrogen atom in its ground state is –13.6 eV, the energy of the level corresponding to n = 7 is

• a) –0.28 eV
• b) –0.85 eV
• c) –5.40 eV
• d) –0.544 eV

Answer: –0.28 eV

Question: Which series of hydrogen atom lie in infrared region?

• a) Brackett, Paschen and Pfund
• b) Lyman
• c) Balmer
• d) All of these

Answer: Brackett, Paschen and Pfund

Question: Total energy of an electron in the hydrogen atom in the ground state is –13.6 eV. The potential energy of this electron is

• a) –27.2 eV
• b) –13.6 eV
• c) 0
• d) 13.6 eV

Answer: –27.2 eV

Question: If potential energy of an electron in a hydrogen atom in first excited state is taken to be zero, kinetic energy (in eV) of an electron in ground state will be

• a) 13.6 eV
• b) 10.2 eV
• c) 3.4 eV
• d) 5.1 eV

Answer: 13.6 eV

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Maximum wavelength in balmer series of hydrogen spectrum is

• a) 6561 Å
• b) 8201 Å
• c) 3645 Å
• d) 912 Å

Answer: 6561 Å

Question: In Rutherford’s experiment, number of particles scattered at 90º angle are x per second. Number particles scattered per second at angle 60º is

• a) 4 x
• b) 16 x
• c) x
• d) 8 x

Answer: 4 x

Question: Compton effect supports that

• a) Photons have momentum
• b) X-rays can easily penetrate matter
• c) X-rays have high frequency compared to visible light
• d) X-rays are transverse waves

Answer: Photons have momentum

Question: Which is the correct relation between de-Broglie wavelength of an electron in the n th Bohr orbit and radius of the orbit R?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) 0.76 Å
• b) 0.82 Å
• c) 0.88 Å
• d) 0.66 Å

Answer: 0.76 Å

Question: Hydrogen atoms are excited from ground state to the principal quantum number 5. Number of spectral lines observed will be

• a) 10
• b) 8
• c) 4
• d) 5

Answer: 10

Question:

• a) n⁶
• b) n⁸
• c) n⁴
• d) None of these

Answer: n⁶

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• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: An electron makes a transition from orbit n = 4 to the orbit n = 2 of a hydrogen atom. What is the wavelength of the emitted radiations? (R = Rydberg’s constant)

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

More Questions..............................

Question: When a hydrogen atom is raised from the ground state to an excited state

• a) The P.E. increases and K.E. decreases
• b) Both K.E. and P.E, decrease
• c) The P.E. decreases and K.E. increases
• d) Both K.E. and P.E. increase

Answer: The P.E. increases and K.E. decreases

Question:

• a) 1, 2, 3
• b) 1, 4, 6
• c) 1, 2, 3, 4, 5, 6
• d) 4, 5, 6

Answer: 1, 2, 3

Question: The energy of a hydrogen atom in its ground state is – 13.6 eV. The energy of the level corresponding to the quantum number n = 2 in the hydrogen atom is

• a) – 3.4 eV
• b) 0.54 eV
• c) – 2.72 eV
• d) – 0.85 eV

Answer: – 3.4 eV

Question: According to Bohr’s principle, the relation between principal quantum number (n) and radius of orbit is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: When hydrogen atom is in its first excited level, its radius is ……………. of the Bohr radius.

• a) 4 times
• b) Same
• c) Half
• d) Twice

Answer: 4 times

Question:

• a) 19 : 81
• b) 81 : 19
• c) 10 : 11
• d) 15 : 16

Answer: 19 : 81

Question:

• a)

  

• b)

  

• c)

  

• d) Zero

Answer:

Question: Maximum frequency of emission is obtained for the transition

• a) n = 2 to n = 1
• b) n = 6 to n = 2
• c) n = 1 to n = 2
• d) n = 2 to n = 6

Answer: n = 2 to n = 1

Question: When an electron do transition from n = 4 to n = 2, then emitted line in spectrum will be

• a) Second line of Balmer series
• b) Second line of Paschen series
• c) First line of Lyman series
• d) First line of Paschen series

Answer: Second line of Balmer series

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The Bohr model of atoms

• a) Assumes that the angular momentum of electrons is quantized
• b) Uses Einstein’s photo-electric equation
• c) Predicts continuous emission spectra for atoms
• d) Predicts the same emission spectra for all types of atom

Answer: Assumes that the angular momentum of electrons is quantized

Question:

• a) 1.9 eV
• b) 3.4 eV
• c) 0.85 eV
• d) 1.5 eV

Answer: 1.9 eV

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Ionization potential of hydrogen atom is 13.6 eV. Hydrogen atoms in the ground state are excited by monochromatic radiation of photon energy 12.1 eV. According to Bohr’s theory, the spectral lines emitted by hydrogen will be

• a) Three
• b) Four
• c) Two
• d) One

Answer: Three

Question: In which of the following systems will the radius of the first orbit (n = 1) be minimum?

• a) Doubly ionized lithium
• b) Singly Ionized helium
• c) Hydrogen atom
• d) Deuterium atom

Answer: Doubly ionized lithium

Question: The total energy of electron in the ground state of hydrogen atom is –13.6 eV. The kinetic energy of an electron in the first excited state is

• a) 3.4 eV
• b) 1.7 eV
• c) 13.6 eV
• d) 6.8 eV

Answer: 3.4 eV

Question: The ionization energy of the electron in the hydrogen atom in its ground state is 13.6 eV. The atoms are excited to higher energy levels to emit radiations of 6 wavelengths. Maximum wavelength of emitted radiation corresponds to the transition between

• a) n = 4 to n = 3 states
• b) n = 3 to n = 2 states
• c) n = 2 to n = 1 state
• d) n = 3 to n = 1 state

Answer: n = 4 to n = 3 states

Question: The energy of a hydrogen atom in the ground state is –13.6 eV. The energy of a He+ ion in the first excited state will be

• a) –13.6 eV
• b) –27.2 eV
• c) –54.4 eV
• d) –6.8 eV

Answer: –13.6 eV

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) 7 V
• b) 17.2 V
• c) 12.1 V
• d) 5.1 V

Answer: 7 V

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• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: An electron of a stationary hydrogen atom passes from the fifth energy level to the ground level. The velocity that the atom acquired as a result of photon emission will be

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The transition from the state n = 3 to n = 1 in a hydrogen like atom results in ultraviolet radiation. Infrared radiation will be obtained in the transition from

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The wavelength of the first line of Lyman series for hydrogen atom is equal to that of the second line of Balmer series for a hydrogen like ion. The atomic number Z of hydrogen like ion is

• a) 2
• b) 3
• c) 4
• d) 1

Answer: 2

Question: Out of the following which one is not a possible energy for a photon to be emitted by hydrogen atom according to Bohr's atomic model?

• a) 11.1 eV
• b) 1.9 eV
• c) 0.65 eV
• d) 13.6 eV

Answer: 11.1 eV

Question: The ground state energy of hydrogen atom is –13.6 eV. When its electron is in the first excited state, its excitation energy is

• a) 10.2 eV
• b) 6.8 eV
• c) 3.4 eV
• d) 0

Answer: 10.2 eV

Question: The ratio of radii of first shell of H atom and that of fourth shell of He⁺ ion is

• a) 1 : 8
• b) 1 : 4
• c)

  

• d) 1 : 3

Answer: 1 : 8

Question: The ionisation energy of 10 times ionised sodium atom is

• a) 13.6 × (11)² eV
• b) 13.6 × 11 eV
• c) 13. 6 eV
• d)

  

Answer: 13.6 × (11)² eV

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The ratio of wavelengths of the 1st line of Balmer series and that of the 1st line of Paschen series is

• a) 7 : 20
• b) 4 : 7
• c) 7 : 4
• d) 20 : 7

Answer: 7 : 20

Question: The shortest wavelength of Balmer series of H-atom is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) 2
• b) 3
• c) 4
• d) 8

Answer: 2

Question:

• a) 91.8 eV
• b) 13.6 eV
• c) 3.4 eV
• d) 10.2 eV

Answer: 91.8 eV

Question: The absorption transition between the first and the fourth energy states of hydrogen atom are 3. The emission transition between these states will be

• a) 6
• b) 5
• c) 4
• d) 3

Answer: 6

Question: When a hydrogen atom emits a photon of energy 12.1 eV, its orbital angular momentum changes by (where h is Planck’s constant)

• a)

  

• b)

  

• c)

  

• d)

  

Answer: