Question 1

The Lyman series is formed by electron transitions in hydrogen that
A)end on the n = 1 shell.
B)begin on the n = 1 shell.
C)end on the n = 2 shell.
D)begin on the n = 2 shell.
E)are between the n = 1 and n = 3 shells.

Accepted Answer

The Lyman series in hydrogen is characterized by electron transitions that end on the n = 1 energy level (shell), from higher energy levels.

Question 2

If a proton and an electron have the same de Broglie wavelengths,which one is moving faster?
A)the electron
B)the proton
C)They both have the same speed.

Accepted Answer

According to de Broglie's formula, the wavelength of a particle is inversely proportional to its momentum. As the masses of the proton and electron are vastly different, they would have the same de Broglie wavelength at different speeds. Since the de Broglie wavelength is the same for both, the electron must be moving faster than the proton to compensate for its lesser mass.

Question 3

The Balmer series is formed by electron transitions in hydrogen that
A)end on the n = 1 shell.
B)begin on the n = 1 shell.
C)end on the n = 2 shell.
D)begin on the n = 2 shell.
E)are between the n = 1 and n = 3 shells.

Accepted Answer

The Balmer series is formed by electron transitions in hydrogen that end on the n = 2 shell. The Balmer series includes transitions from higher energy levels to the n=2 energy level.

Question 4

If the maximum possible accuracy in measuring the velocity of a particle increases,the maximum possible accuracy in measuring its position will
A)increase.
B)decrease.
C)not be affected.

Accepted Answer

This is a consequence of Heisenberg's Uncertainty Principle, which states that the more accurately we know the position of a particle, the less accurately we can know its momentum (which is related to velocity). Similarly, the more accurately we know the momentum of a particle, the less accurately we can know its position. Therefore, if the accuracy in measuring velocity increases, the accuracy in measuring position must decrease according to the uncertainty principle.

Question 5

Which of the following actions will increase the de Broglie wavelength of a speck of dust? (There could be more than one correct choice.)
A)Increase its mass.
B)Increase its speed.
C)Decrease its mass.
D)Decrease its speed.
E)Decrease its momentum.

Accepted Answer

The answer of Which of the following actions will increase...

Question 6

To which of the following values of n does the longest wavelength in the Balmer series correspond?
A)3
B)5
C)1
D)7
E)∞ (very large)

Accepted Answer

The answer of To which of the following values of...

Question 7

The energy difference between adjacent orbit radii in a hydrogen atom
A)increases with increasing values of n.
B)decreases with increasing values of n.
C)remains constant for all values of n.
D)varies randomly with increasing values of n.

Accepted Answer

According to the Bohr model, the energy of an electron in a hydrogen atom is given by E = -13.6/n^2 eV, where n is the principal quantum number. The energy difference between adjacent orbit radii is given by the difference in energy levels between the two orbits. Therefore, the energy difference between adjacent orbit radii decreases with increasing values of n, as the energy levels get closer together.

Question 8

A proton and an electron are both accelerated to the same final speed.If λ_p is the de Broglie wavelength of the proton and λ_e is the de Broglie wavelength of the electron,then A)λ_p > λ_e. B)λ_p = λ_e. C)λ_p < λ_e.

Accepted Answer

The de Broglie wavelength, λ, is given by λ = h/p, where h is Planck's constant and p is the momentum of the particle. Since momentum p = mv (mass times velocity), and both particles are given the same final speed, the lighter particle (electron) will have a smaller momentum and thus a larger de Broglie wavelength compared to the heavier particle (proton). Therefore, λ_proton < λ_electron.

Question 9

If the maximum possible accuracy in measuring the lifetime of a particle increases,the maximum possible accuracy in measuring its energy will
A)increase.
B)decrease.
C)not be affected.

Accepted Answer

According to the Heisenberg Uncertainty Principle, the product of the uncertainties in time and energy is greater than or equal to a constant (ħ/2). Therefore, if the uncertainty in measuring the lifetime (time) of a particle decreases (meaning the accuracy increases), the uncertainty in measuring its energy must increase (meaning the accuracy decreases) to satisfy the principle.

Question 10

If the wavelength of a photon in vacuum is the same as the de Broglie wavelength of an electron,which one is traveling faster through space?
A)The electron because it has more mass.
B)The photon because photons always travel through space faster than electrons.
C)They both have the same speed.

Accepted Answer

Photons always travel at the speed of light in a vacuum, which is the maximum speed anything can travel through space. Electrons, having mass, cannot reach this speed.

Question 11

When an atom changes its energy state from n = 4 to n = 2
A)a photon is emitted.
B)a photon is absorbed.
C)two photons are emitted.
D)two photons are absorbed.
E)None of the given answers are correct.

Accepted Answer

When an electron in an atom transitions from a higher energy level (here, n = 4) to a lower energy level (here, n = 2), energy is released in the form of a photon. Therefore, the correct choice is A, a photon is emitted.

Question 12

A proton and an electron are both accelerated to the same final kinetic energy.If λ_p is the de Broglie wavelength of the proton and λ_e is the de Broglie wavelength of the electron,then A)λ_p > λ_e. B)λ_p = λ_e. C)λ_p < λ_e.

Accepted Answer

The de Broglie wavelength, λ, is given by λ = h/p, where h is Planck's constant and p is the momentum of the particle. For the same kinetic energy, a lighter particle (electron) will have a higher velocity than a heavier particle (proton), resulting in a larger momentum for the electron. Since the wavelength is inversely proportional to momentum, the electron will have a shorter de Broglie wavelength than the proton.

Question 13

If the maximum possible accuracy in measuring the position of a particle increases,the maximum possible accuracy in measuring its velocity will
A)increase.
B)decrease.
C)not be affected.

Accepted Answer

According to the Heisenberg Uncertainty Principle, the more precisely the position of a particle is known, the less precisely its momentum (and hence velocity, since velocity is directly related to momentum for a given mass) can be known. Therefore, if the accuracy in measuring the position increases, the accuracy in measuring its velocity must decrease.

Question 14

Hydrogen atoms can emit four spectral lines with visible colors from red to violet.These four visible lines emitted by hydrogen atoms are produced by electrons
A)that start in the n = 2 level.
B)that end up in the n = 2 level.
C)that end up in the n = 3 level.
D)that end up in the ground state.
E)that start in the ground state.

Accepted Answer

The four visible lines emitted by hydrogen atoms are produced when electrons transition from higher energy levels to the n=2 energy level. Each of these transitions corresponds to a specific wavelength of light, which appears as a different color in the visible spectrum. Therefore, the correct option is the one where the electrons end up in the n=2 energy level, which is option B.

Question 15

To which of the following values of n does the shortest wavelength in the Balmer series correspond?
A)3
B)5
C)7
D)1
E)∞ (very large)

Accepted Answer

The shortest wavelength in the Balmer series corresponds to the transition from the highest energy level (n = ∞) to n = 2. This is because the energy difference (and thus the frequency and inversely the wavelength) is greatest for transitions ending at n = 2 from the highest possible energy level.

Question 16

The Paschen series is formed by electron transitions that
A)end on the n = 1 shell.
B)begin on the n = 1 shell.
C)end on the n = 2 shell.
D)begin on the n = 3 shell.
E)end on the n = 3 shell.

Accepted Answer

The Paschen series involves electron transitions that begin on the n = 3 shell and end on the n = 4 shell. Therefore, the correct choice is E, which states that these transitions end on the n = 3 shell.

Question 17

Protons are being accelerated in a particle accelerator.When the energy of the protons is doubled,their de Broglie wavelength will
A)increase by a factor of 4.
B)increase by a factor of 2.
C)decrease by a factor of 2.
D)increase by a factor of $\sqrt { 2 }$
E)decrease by a factor of $\sqrt { 2 }$

Accepted Answer

The de Broglie wavelength $\lambda$ is given by $\lambda = \frac{h}{p}$, where $h$ is Planck's constant and $p$ is the momentum of the particle. For a proton in a particle accelerator, its kinetic energy $E_k$ is related to its momentum by $E_k = \frac{p^2}{2m}$, where $m$ is the mass of the proton. If the energy of the protons is doubled, the new kinetic energy is $2E_k$, leading to a new momentum $p' = \sqrt{2m \cdot 2E_k} = \sqrt{2}p$. Thus, the new de Broglie wavelength $\lambda' = \frac{h}{p'} = \frac{h}{\sqrt{2}p} = \frac{\lambda}{\sqrt{2}}$, meaning the wavelength decreases by a factor of $\sqrt{2}$.

Question 18

If the maximum possible accuracy in measuring the energy of a particle increases,the maximum possible accuracy in measuring its lifetime will
A)increase.
B)decrease.
C)not be affected.

Accepted Answer

According to Heisenberg's uncertainty principle, there is a fundamental trade-off between the accuracy with which we can measure the energy and the accuracy with which we can measure the lifetime of a particle. Increasing the accuracy in measuring the energy of a particle narrows down the range of possible values for its momentum, which in turn decreases the range of possible lifetimes. Therefore, the maximum possible accuracy in measuring the lifetime of a particle will decrease as the maximum possible accuracy in measuring its energy increases.

Question 19

If a proton and an electron have the same speed,which one has the longer de Broglie wavelength?
A)the electron
B)the proton
C)It is the same for both of them.

Accepted Answer

The de Broglie wavelength is inversely proportional to the mass of the particle. Since the electron has a smaller mass than the proton, it will have a longer de Broglie wavelength at the same speed.

Question 20

Protons are being accelerated in a particle accelerator.When the speed of the protons is doubled,their de Broglie wavelength will
A)increase by a factor of 4.
B)increase by a factor of 2.
C)decrease by a factor of 2.
D)increase by a factor of $\sqrt { 2 }$
E)decrease by a factor of $\sqrt { 2 }$

Accepted Answer

The de Broglie wavelength $\lambda$ is inversely proportional to the momentum $p$ of a particle, given by $\lambda = \frac{h}{p}$, where $h$ is Planck's constant. Since the momentum of a particle is the product of its mass and velocity ($p = mv$), doubling the speed of the protons doubles their momentum. Therefore, their de Broglie wavelength will decrease by a factor of 2, as the relationship between wavelength and momentum is inversely proportional.

Quiz 28: Atomic Physics

The Lyman series is formed by electron transitions in hydrogen that

If a proton and an electron have the same de Broglie wavelengths,which one is moving faster?

The Balmer series is formed by electron transitions in hydrogen that

If the maximum possible accuracy in measuring the velocity of a particle increases,the maximum possible accuracy in measuring its position will

Which of the following actions will increase the de Broglie wavelength of a speck of dust? (There could be more than one correct choice.)

To which of the following values of n does the longest wavelength in the Balmer series correspond?

The energy difference between adjacent orbit radii in a hydrogen atom

A proton and an electron are both accelerated to the same final speed.If λp is the de Broglie wavelength of the proton and λe is the de Broglie wavelength of the electron,then

If the maximum possible accuracy in measuring the lifetime of a particle increases,the maximum possible accuracy in measuring its energy will

If the wavelength of a photon in vacuum is the same as the de Broglie wavelength of an electron,which one is traveling faster through space?

When an atom changes its energy state from n = 4 to n = 2

A proton and an electron are both accelerated to the same final kinetic energy.If λp is the de Broglie wavelength of the proton and λe is the de Broglie wavelength of the electron,then

If the maximum possible accuracy in measuring the position of a particle increases,the maximum possible accuracy in measuring its velocity will

Hydrogen atoms can emit four spectral lines with visible colors from red to violet.These four visible lines emitted by hydrogen atoms are produced by electrons

To which of the following values of n does the shortest wavelength in the Balmer series correspond?

The Paschen series is formed by electron transitions that

Protons are being accelerated in a particle accelerator.When the energy of the protons is doubled,their de Broglie wavelength will

If the maximum possible accuracy in measuring the energy of a particle increases,the maximum possible accuracy in measuring its lifetime will

If a proton and an electron have the same speed,which one has the longer de Broglie wavelength?

Protons are being accelerated in a particle accelerator.When the speed of the protons is doubled,their de Broglie wavelength will

A proton and an electron are both accelerated to the same final speed.If λ_p is the de Broglie wavelength of the proton and λ_e is the de Broglie wavelength of the electron,then

A proton and an electron are both accelerated to the same final kinetic energy.If λ_p is the de Broglie wavelength of the proton and λ_e is the de Broglie wavelength of the electron,then