The Bohr Model (7.1.6) Flashcards
• The Bohr model provided the conceptual bridge from classical theoretical physics
to quantum mechanics. It is important because it introduced the idea of quantized
energy states for electrons in atoms.
• The Bohr model provided the conceptual bridge from classical theoretical physics
to quantum mechanics. It is important because it introduced the idea of quantized
energy states for electrons in atoms.
• Bohr’s model worked very well for explaining atoms and ions having a single
electron, such as H, He+
, Li2+, and Be3+.
• Bohr’s model worked very well for explaining atoms and ions having a single
electron, such as H, He+
, Li2+, and Be3+.
• Bohr’s model was inadequate for explaining atomic spectra of other atoms or
ions.
• Bohr’s model was inadequate for explaining atomic spectra of other atoms or
ions.
Neils Bohr explained the observation that the
missing spectral frequencies of sunlight are
exactly the same frequencies as those emitted by
the hydrogen atom.
The Bohr model provided the conceptual bridge
from classical theoretical physics to quantum
mechanics. It is important because it introduced the
idea of quantized energy states for electrons in
atoms.
Bohr’s postulated that the angular momentum of
electrons is quantized, so the distance of electrons
from the nucleus is quantized, and the energy of
electrons is quantized.
The Bohr model asserted that only certain orbits
were allowed. It accounted for potential energy,
kinetic energy, and the fact that only specific
energy levels were observed. It also stated that
energy was directly proportional to the square of the
nuclear charge divided by the square of the
principal quantum number, which must be a
positive integer.
The Bohr model explained all lines in both the
visible and the non-visible spectra of hydrogen (the
Balmer series, the Lyman series, and the Paschen
series).
While the Bohr model works well for predicting
properties of hydrogen, it does not work for
elements with more than one electron.
The Bohr model assumed that the electron was a
particle with a fixed distance from the nucleus.
However, just like light, electrons have both particle
properties and wave properties.
Neils Bohr explained the observation that the
missing spectral frequencies of sunlight are
exactly the same frequencies as those emitted by
the hydrogen atom.
The Bohr model provided the conceptual bridge
from classical theoretical physics to quantum
mechanics. It is important because it introduced the
idea of quantized energy states for electrons in
atoms.
Bohr’s postulated that the angular momentum of
electrons is quantized, so the distance of electrons
from the nucleus is quantized, and the energy of
electrons is quantized.
The Bohr model asserted that only certain orbits
were allowed. It accounted for potential energy,
kinetic energy, and the fact that only specific
energy levels were observed. It also stated that
energy was directly proportional to the square of the
nuclear charge divided by the square of the
principal quantum number, which must be a
positive integer.
The Bohr model explained all lines in both the
visible and the non-visible spectra of hydrogen (the
Balmer series, the Lyman series, and the Paschen
series).
While the Bohr model works well for predicting
properties of hydrogen, it does not work for
elements with more than one electron.
The Bohr model assumed that the electron was a
particle with a fixed distance from the nucleus.
However, just like light, electrons have both particle
properties and wave properties.
What is Wave-Particle Duality?
Matter and energy behave as both waves and particles.
Why is the Bohr Atom Model Wrong?
It explained atoms as if electrons were in a fixed spot and it only applied to hydrogen.
According to the Bohr model of the atom, when does the energy of an electron in an atom decrease?
When the charge of the nucleus increases or the quantum number n decreases. (A)
What can you conclude from the fact that the emission spectrum of hydrogen corresponds to the Fraunhofer lines in sunlight?
Sunlight passes through hydrogen gas before it reaches Earth. (D)
There are four Fraunhofer lines in the visible portion of the solar spectrum that correspond to the emission spectrum of hydrogen gas. However, scientists have discovered approximately 25,000 dark lines in the complete solar spectrum (one that includes the visible and the invisible portions). What can you conclude based on this information?
The sun’s atmosphere contains a variety of gases. (A)
Suppose an electron with a quantum number of n = 3 absorbs a photon with energy of 1.55 × 10−19 J and then emits a photon with energy of 4.58 × 10−19 J. What is the final quantum number of the electron after emission?
2 (C)
The emission spectrum of which of the following atoms or ions could not be predicted by the Bohr model?
a neutral isotope of helium containing one neutron (C)
What frequency of light will be emitted from a lithium ion (Li 2+ ) when its electron drops from an energy level of n = 5 to an energy level of n = 2?
6.22 × 10^15 s^−1 (C)
Hydrogen gas emits four lines in the visible region of the spectrum (at 410 nm, 434 nm, 486 nm, and 656 nm). Which of the following best explains why hydrogen does not emit light with a wavelength of 680 nm?
No two energy levels are separated by a difference corresponding to a 680 nm photon. (C)
How much energy must an electron in a hydrogen atom absorb to move from the first (or lowest) energy level to the third energy level?
1.94 × 10^−18 J (B)
Which of the following transitions of an electron in a hydrogen atom will emit the longest wavelength of light?
from n = 5 to n = 3 (D)
