Bohr’s Theory of Hydrogen Atom
Physics ⇒ Modern Physics
Bohr’s Theory of Hydrogen Atom starts at 11 and continues till grade 12.
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According to Bohr’s postulates, the angular momentum of an electron in a stationary orbit is quantized and given by L = n×h/2π. What does 'n' represent in this formula?
Calculate the energy of the photon emitted when an electron in a hydrogen atom jumps from n = 5 to n = 2.
Calculate the speed of the electron in the first Bohr orbit of hydrogen. (Given: e = 1.6×10-19 C, h = 6.63×10-34 J·s, me = 9.1×10-31 kg, ε0 = 8.85×10-12 C2/N·m2)
Calculate the wavelength of the photon emitted when an electron in a hydrogen atom jumps from n = 3 to n = 2. (Use hc = 1240 eV·nm)
Describe one experimental observation that led to the development of Bohr’s model of the atom.
Describe the process by which Bohr’s model explains the emission spectrum of hydrogen.
Explain why the Bohr model is successful in explaining the hydrogen spectrum but fails for multi-electron atoms.
Explain why the energy of the electron in the Bohr model is negative.
The frequency of the radiation emitted when an electron jumps from a higher energy orbit to a lower one is given by which formula?
(1) f = E/h
(2) f = c/λ
(3) f = (Ei - Ef)/h
(4) f = h/(Ei - Ef)
Which of the following is a correct expression for the radius of the nth orbit in a hydrogen atom?
(1) rn = n2a0
(2) rn = n·a0
(3) rn = a0/n
(4) rn = n2/a0
Which of the following is NOT an assumption of Bohr’s theory of the hydrogen atom?
(1) Electrons revolve in certain stable orbits without radiating energy.
(2) The energy of the electron is continuous.
(3) The angular momentum of the electron is quantized.
(4) Radiation is emitted or absorbed only when an electron jumps between orbits.
Which of the following is NOT explained by Bohr’s model?
(1) Hydrogen spectrum
(2) Fine structure of spectral lines
(3) Ionization energy of hydrogen
(4) Radius of electron orbits
Fill in the blank: The Balmer series of hydrogen corresponds to transitions where the final state is n = ______.
Fill in the blank: The energy of the electron in the nth orbit of a hydrogen atom is given by En = -13.6 eV / n2. For n = 2, E2 = ______ eV.
Fill in the blank: The minimum energy required to remove an electron from the ground state of a hydrogen atom is called the ______ energy.
Fill in the blank: The transition of an electron from n = 2 to n = 1 in hydrogen emits a photon in the ______ region of the electromagnetic spectrum.
True or False: According to Bohr’s theory, the electron emits energy continuously as it revolves in its orbit.
True or False: According to Bohr’s theory, the electron in a hydrogen atom can exist in any orbit with any energy.
True or False: The Bohr model assumes that the nucleus is stationary and infinitely massive compared to the electron.
True or False: The Bohr model can accurately predict the spectra of all multi-electron atoms.
