Question 1

If a target element with atomic number Z used in the production of x-rays is replaced by another element for which the atomic number = 5Z,by what factor is the wavelength of the K-alpha x-ray line changed?
A) 1/25
B) 1/5
C) 1
D) 5
E) ​25

Accepted Answer

The wavelength of the K-alpha x-ray line is inversely proportional to the square of the atomic number (Z) of the target element. If the atomic number is increased by a factor of 5, the wavelength decreases by a factor of 5^2 = 25. Thus, the wavelength changes by a factor of 1/25.

Question 2

The quantum mechanical model of the hydrogen atom suggests a visual picture of the electron as which of the following?
A) raisin in pudding
B) probability cloud
C) planetary orbiting body
D) light quantum

Accepted Answer

The quantum mechanical model of the hydrogen atom describes the electron not as a discrete particle but rather as a probability cloud, meaning the electron is more likely to be found in certain regions of space than others.

Question 3

If the principal quantum number for hydrogen is 7,which one of the following is not a permitted orbital magnetic quantum number for that atom?
A) 10
B) -2
C) 0
D) 5
E) ​3

Accepted Answer

The maximum value of the magnetic quantum number for an atom with a principal quantum number of 7 is 6, so 10 is not a permitted value. The other answer choices (B, C, D, and E) are all within the allowed range.

Question 4

The quantum mechanical model of the hydrogen atom requires that if the orbital quantum number = 6,there are permitted how many possible substates?
A) 6
B) 12
C) 26
D) 13
E) ​36

Accepted Answer

The answer of The quantum mechanical model of the hydrogen...

Question 5

The quantum mechanical model of the hydrogen atom requires that if the orbital quantum number = 7,there will be how many permitted orbital magnetic quantum numbers allowed?
A) 6
B) 7
C) 14
D) 15
E) ​49

Accepted Answer

The magnetic quantum number (m) ranges from -l to +l, where l is the orbital quantum number. For l = 7, m ranges from -7 to +7, which gives 15 possible values.

Question 6

The x-rays that occur when a high energy electron beam is incident on a metal target will show what type of spectrum?
A) continuous
B) line
C) continuous spectrum superimposed with a line spectrum
D) absorption

Accepted Answer

When a high energy electron beam is incident on a metal target, it interacts with the electrons in the metal atoms and in the process, energy is released in the form of x-rays. These x-rays can have a continuous spectrum or a line spectrum, depending on the type of metal used as the target. In most cases, the spectrum will be a combination of both continuous and line spectra, as the emitted x-rays will be superimposed on top of the background continuum.

Question 7

The restriction that no more than one electron may occupy a given quantum state in an atom was first stated by which of the following scientists?
A) Bohr
B) de Broglie
C) Heisenberg
D) Pauli

Accepted Answer

This is known as the Pauli Exclusion Principle, named after Wolfgang Pauli who first stated it in 1925. Bohr's model of the atom explained the electron's energy levels, de Broglie proposed the wave-particle duality of matter, and Heisenberg formulated the uncertainty principle.

Question 8

When a hydrogen atom absorbs a photon that raises it to the n = 4 state,how many different energies are possible for the photon(s)that may be emitted as the atom eventually returns to the ground state?
A) 3
B) 4
C) 5
D) 8
E) T​he correct answer is not given.

Accepted Answer

The answer of When a hydrogen atom absorbs a photon...

Question 9

In an x-ray machine,electrons are accelerated and then fired so that they are incident on a metal target.Which part of the process produces the characteristic x-ray spectra?
A) The incident electron loses energy.
B) The incident electron knocks an electron out of one of the metal atoms.
C) A vacancy in an energy level in a metal atom is filled.
D) The incident electron emits an x-ray.

Accepted Answer

The characteristic x-ray spectra is produced when a vacancy in an energy level in a metal atom is filled. This occurs after the incident electron knocks out an inner shell electron of the metal atom, creating a vacancy. When an outer shell electron fills the vacancy, it emits a photon of energy, which constitutes the characteristic x-ray spectra.

Question 10

In a plot of probability of finding the electron in the hydrogen ground state versus the distance from the nucleus,the maximum occurs: A) at a₀,the first Bohr radius. B) at slightly less than a₀. C) at slightly more than a₀. D) at 2 a₀.

Accepted Answer

The probability of finding the electron in the hydrogen ground state is given by the square of the wave function, which depends on the distance from the nucleus. The maximum value of the wave function, and therefore the maximum probability, occurs at the most probable distance from the nucleus, which for the ground state of hydrogen is at a distance of a₀, the first Bohr radius.

Question 11

The ground state electronic configuration for magnesium is 1s²2s²2p⁶3s².What is the orbital quantum number of the last (3s²)electron? A) 2 B) 0 C) 1 D) 3 E) not enough information

Accepted Answer

The orbital quantum number (azimuthal quantum number, l) for an s orbital is 0. Since the last electron is in a 3s orbital, its orbital quantum number is 0.

Question 12

The ground state electronic configuration for boron is 1s²2s²2p¹.In which shell is the last (2p¹)electron? A) K B) M C) L D) N E) O

Accepted Answer

The shell labels K, L, M, N, O... correspond to the principal quantum numbers n=1,2,3,4,5... respectively. The last electron in the ground state electronic configuration of boron is in the 2p sub-shell, which falls under n=2. Therefore, the last electron is in the L shell.

Question 13

Characteristic x-rays are the result of:
A) outer electron transitions.
B) inner electron transitions.
C) nuclear electron states.
D) buckytubes.

Accepted Answer

Characteristic x-rays are the result of inner electron transitions, specifically when an electron from a higher energy level drops down to fill a vacancy in a lower energy level, releasing energy in the form of an x-ray.

Question 14

How many electrons are in chromium's (atomic number chromium)next to outer shell (n = 3)?
A) 1
B) 14
C) 12
D) 13
E) ​8

Accepted Answer

The answer of How many electrons are in chromium's (atomic...

Question 15

The quantum mechanical model of the hydrogen atom requires that if the principal quantum number = 3,there will be permitted how many orbital magnetic quantum numbers?
A) 2
B) 3
C) 6
D) 5
E) ​7

Accepted Answer

For a given principal quantum number n, the possible values of the azimuthal quantum number l range from 0 to n-1. For n=3, l can be 0, 1, or 2. The magnetic quantum number m_l ranges from -l to +l, giving 1, 3, and 5 values respectively for l=0, 1, and 2. Therefore, the total number of magnetic quantum numbers is 1 + 3 + 5 = 9. However, the question seems to be asking for the number of distinct m_l values for l=2, which is 5.

Question 16

The quantum number that can have only two possible values is the:
A) principal quantum number.
B) orbital quantum number.
C) orbital magnetic quantum number.
D) spin magnetic quantum number.

Accepted Answer

The spin magnetic quantum number is the quantum number that can have only two possible values: +1/2 or -1/2. This quantum number describes the electron spin, which is either up or down. The other quantum numbers listed (principal, orbital, and orbital magnetic) can take on multiple values.

Question 17

Which of the following demonstrated the relation between the atomic number of a given element and the wavelength of the K-alpha x-ray photon emitted by that element?
A) Bohr
B) Compton
C) Moseley
D) Pauli

Accepted Answer

Moseley's experiment demonstrated a relationship between the atomic number (Z) of an element and the wavelength of the K-alpha x-ray photon emitted by that element, known as Moseley's law.

Question 18

The quantity ________,where Ψ is the wave function,represents the probability per unit volume of finding an electron in that volume. A) Ψ^1/2 B) Ψ C) Ψ^3/2 D) Ψ²

Accepted Answer

The answer of The quantity ________,where Ψ is the wave...

Question 19

If the energy for the ground state level (n = 1)of hydrogen is −13.6 eV,which of the following gives an approximate value for the energy of an electron of the K shell (n = 1)of the element beryllium for which the atomic number = 4?
A) -122 eV
B) -40.8 eV
C) -218 eV
D) -54.4 eV
E) ​-40.8 eV

Accepted Answer

The answer of If the energy for the ground state...

Question 20

Imagine that an electron had a spin of 5/2 so that its spin quantum number,m_s,could have the following six values: m_s = +5/2,+3/2,+1/2,-1/2,-3/2,and -5/2.If this were true,the first element with a filled shell would be: A) He with 2 electrons. B) Be with 4 electrons. C) C with 6 electrons. D) O with 8 electrons.

Accepted Answer

The answer of Imagine that an electron had a spin...

Quiz 28: Atomic Physics

If a target element with atomic number Z used in the production of x-rays is replaced by another element for which the atomic number = 5Z,by what factor is the wavelength of the K-alpha x-ray line changed?

The quantum mechanical model of the hydrogen atom suggests a visual picture of the electron as which of the following?

If the principal quantum number for hydrogen is 7,which one of the following is not a permitted orbital magnetic quantum number for that atom?

The quantum mechanical model of the hydrogen atom requires that if the orbital quantum number = 6,there are permitted how many possible substates?

The quantum mechanical model of the hydrogen atom requires that if the orbital quantum number = 7,there will be how many permitted orbital magnetic quantum numbers allowed?

The x-rays that occur when a high energy electron beam is incident on a metal target will show what type of spectrum?

The restriction that no more than one electron may occupy a given quantum state in an atom was first stated by which of the following scientists?

When a hydrogen atom absorbs a photon that raises it to the n = 4 state,how many different energies are possible for the photon(s) that may be emitted as the atom eventually returns to the ground state?

In an x-ray machine,electrons are accelerated and then fired so that they are incident on a metal target.Which part of the process produces the characteristic x-ray spectra?

In a plot of probability of finding the electron in the hydrogen ground state versus the distance from the nucleus,the maximum occurs:

The ground state electronic configuration for magnesium is 1s²2s²2p⁶3s².What is the orbital quantum number of the last (3s²) electron?

The ground state electronic configuration for boron is 1s²2s²2p¹.In which shell is the last (2p¹) electron?

Characteristic x-rays are the result of:

How many electrons are in chromium's (atomic number chromium) next to outer shell (n = 3) ?

The quantum mechanical model of the hydrogen atom requires that if the principal quantum number = 3,there will be permitted how many orbital magnetic quantum numbers?

The quantum number that can have only two possible values is the:

Which of the following demonstrated the relation between the atomic number of a given element and the wavelength of the K-alpha x-ray photon emitted by that element?

The quantity ________,where Ψ is the wave function,represents the probability per unit volume of finding an electron in that volume.

If the energy for the ground state level (n = 1) of hydrogen is −13.6 eV,which of the following gives an approximate value for the energy of an electron of the K shell (n = 1) of the element beryllium for which the atomic number = 4?

Imagine that an electron had a spin of 5/2 so that its spin quantum number,m_s,could have the following six values: m_s = +5/2,+3/2,+1/2,-1/2,-3/2,and -5/2.If this were true,the first element with a filled shell would be: