REVIEW QUESTIONS
CHAPTER 2
Electromagnetic Radiation
1. The energy of a photon is greatest in the case of
(A) X–radiation. (B) visible light. (C) ultraviolet (D) infrared
2. A photon of light of 450 nm, when compared to light of wavelength 300 nm, has
(A) a higher frequency. (C) lower energy.
(B) a greater velocity. (D) a shorter wavelength.
3. An infrared wave from the sun has a wavelength of 6250 nm. Calculate the energy of one photon of this
radiation.
(A) 4.1 x 10-39 J (B) 4.1 x 10-30 J (C) 3.2 x 10-29 J (D) 3.2 x 10-20 J
Spectra and Energy Levels
4. Emission spectra (line spectra) may be attributed to an electron
(A) spiraling into a nucleus. (B) changing its atomic energy level.
(C) reversing its direction of spin. (D) escaping from the atom.
5. The existence of discrete (quantized) energy levels in an atom may be inferred from
(A) experiments on the photoelectric effect. (B) diffraction of electrons by crystals.
(C) X-ray diffraction by crystals. (D) atomic line spectra.
6. Helium, has two electrons in the 1s orbital. It can become singly ionized by losing one electron, giving
He+. Which statement about this ion is true?
(A) Its spectrum then resembles the hydrogen spectrum.
(B) The remaining electron is easier to remove.
(C) The nuclear charge has decreased by one.
(D) The remaining electron must remain in the n = 1 quantum level at all times.
(E) It has lost one atomic mass unit.
7. If an electron moves from one energy level in an atom to another energy level more remote from the
nucleus of the same atom
(A) energy is absorbed. (B) energy is liberated.
(C) there is no energy change. (D) the atom must assume a different ionic charge
(E) light of a definite wave length is emitted.
8. Calculate the frequency of a photon absorbed when the hydrogen atom undergoes a transition from n = 2
to n = 4 (ℜ = 1.0968 x 107 m-1)
(A) 2.056 x 106 Hz (B) 2.742 x 106 Hz
(C) 6.169 x 1014 Hz (D) 8.226 x 1014 Hz
, 9. An electron in the n = 6 level emits a photon with a wavelength of 410.2 nm. To what energy level does
the electron move? (ℜ = 1.0968 x 107 m-1)
(A) n=1 (B) n=2 (C) n=3 (D) n =4
10. The energy of the electron in the most stable orbital of the hydrogen atom is –2.18 x 10–18 J. The energy
of the electron after promotion to the next highest orbital is (in J):
(A) 0 (B) –5.44 x 10-19 (C) –2.18 x 10–18 (D) –1.55 x 10-18 (E) –4.36 x 10-18
11. Which electron transition is associated with the largest emission of energy?
(A) n = 2 to n = 1 (C) n = 2 to n = 4
(B) n = 2 to n = 3 (D) n = 3 to n = 2
12. The energy of the hydrogen atom in the ground state (n = l) is –21.79 x 10–19 J. A particle strikes a
hydrogen atom and excites the electron to its 5th energy level (n = 5) corresponding to an energy of –
0.87 x 10–19 J. If the electron returns to the ground state in one step, what is the energy of the photon
emitted?
(A) 4.18 x 10–19 J (B) 20.92 x10–19 J (C) 5.48 x10–19 J (D) 2.27 x 10–19 J
13. Who was the first to propose that electrons in an atom could have only certain energies?
(A) Planck (B) Einstein (C) Bohr (D) Rydberg
14. A model that successfully explained the photoelectric effect was proposed by:
(A) Planck (B) Einstein (C) Compton (D) Rydberg
15. The concept that particles of matter could have wave properties was proposed by
(A) Einstein (B) Planck (C) de Broglie (D) Heisenberg
16. The principle that one cannot know that exact position and velocity of a particle simultaneously was
proposed by
(A) Einstein (B) Schrodinger (C) de Broglie (D) Heisenberg
Quantum Numbers
17. Which set of quantum numbers is possible for an electron in an atom?
(A) n = 3, l = 0, ml = 1 , ms = –1/2 (B) n = 2, l = 2, ml = –2 , ms = –1/2
(C) n = 5, l = 2, ml = 2 , ms = +1/2 (D) n = 4, l = 3, ml = –4 , ms = –1/2
18. Which quantum number is associated with the size of an orbital?
(A) n (B) l (C) ml (D) ms
CHAPTER 2
Electromagnetic Radiation
1. The energy of a photon is greatest in the case of
(A) X–radiation. (B) visible light. (C) ultraviolet (D) infrared
2. A photon of light of 450 nm, when compared to light of wavelength 300 nm, has
(A) a higher frequency. (C) lower energy.
(B) a greater velocity. (D) a shorter wavelength.
3. An infrared wave from the sun has a wavelength of 6250 nm. Calculate the energy of one photon of this
radiation.
(A) 4.1 x 10-39 J (B) 4.1 x 10-30 J (C) 3.2 x 10-29 J (D) 3.2 x 10-20 J
Spectra and Energy Levels
4. Emission spectra (line spectra) may be attributed to an electron
(A) spiraling into a nucleus. (B) changing its atomic energy level.
(C) reversing its direction of spin. (D) escaping from the atom.
5. The existence of discrete (quantized) energy levels in an atom may be inferred from
(A) experiments on the photoelectric effect. (B) diffraction of electrons by crystals.
(C) X-ray diffraction by crystals. (D) atomic line spectra.
6. Helium, has two electrons in the 1s orbital. It can become singly ionized by losing one electron, giving
He+. Which statement about this ion is true?
(A) Its spectrum then resembles the hydrogen spectrum.
(B) The remaining electron is easier to remove.
(C) The nuclear charge has decreased by one.
(D) The remaining electron must remain in the n = 1 quantum level at all times.
(E) It has lost one atomic mass unit.
7. If an electron moves from one energy level in an atom to another energy level more remote from the
nucleus of the same atom
(A) energy is absorbed. (B) energy is liberated.
(C) there is no energy change. (D) the atom must assume a different ionic charge
(E) light of a definite wave length is emitted.
8. Calculate the frequency of a photon absorbed when the hydrogen atom undergoes a transition from n = 2
to n = 4 (ℜ = 1.0968 x 107 m-1)
(A) 2.056 x 106 Hz (B) 2.742 x 106 Hz
(C) 6.169 x 1014 Hz (D) 8.226 x 1014 Hz
, 9. An electron in the n = 6 level emits a photon with a wavelength of 410.2 nm. To what energy level does
the electron move? (ℜ = 1.0968 x 107 m-1)
(A) n=1 (B) n=2 (C) n=3 (D) n =4
10. The energy of the electron in the most stable orbital of the hydrogen atom is –2.18 x 10–18 J. The energy
of the electron after promotion to the next highest orbital is (in J):
(A) 0 (B) –5.44 x 10-19 (C) –2.18 x 10–18 (D) –1.55 x 10-18 (E) –4.36 x 10-18
11. Which electron transition is associated with the largest emission of energy?
(A) n = 2 to n = 1 (C) n = 2 to n = 4
(B) n = 2 to n = 3 (D) n = 3 to n = 2
12. The energy of the hydrogen atom in the ground state (n = l) is –21.79 x 10–19 J. A particle strikes a
hydrogen atom and excites the electron to its 5th energy level (n = 5) corresponding to an energy of –
0.87 x 10–19 J. If the electron returns to the ground state in one step, what is the energy of the photon
emitted?
(A) 4.18 x 10–19 J (B) 20.92 x10–19 J (C) 5.48 x10–19 J (D) 2.27 x 10–19 J
13. Who was the first to propose that electrons in an atom could have only certain energies?
(A) Planck (B) Einstein (C) Bohr (D) Rydberg
14. A model that successfully explained the photoelectric effect was proposed by:
(A) Planck (B) Einstein (C) Compton (D) Rydberg
15. The concept that particles of matter could have wave properties was proposed by
(A) Einstein (B) Planck (C) de Broglie (D) Heisenberg
16. The principle that one cannot know that exact position and velocity of a particle simultaneously was
proposed by
(A) Einstein (B) Schrodinger (C) de Broglie (D) Heisenberg
Quantum Numbers
17. Which set of quantum numbers is possible for an electron in an atom?
(A) n = 3, l = 0, ml = 1 , ms = –1/2 (B) n = 2, l = 2, ml = –2 , ms = –1/2
(C) n = 5, l = 2, ml = 2 , ms = +1/2 (D) n = 4, l = 3, ml = –4 , ms = –1/2
18. Which quantum number is associated with the size of an orbital?
(A) n (B) l (C) ml (D) ms
