Question 1

Which of the following is/are the major flaw(s)of the Bohr model of the hydrogen atom?
i.Hydrogen is the only atom that fits the model
ii.Circular orbits violate the Law of Conservation of Energy
iii.It explains atomic line spectra in terms of electron energies
iv.It introduced the idea of quantized electron energy levels in an atom
A)ii only
B)i and ii
C)i and iii
D)iii and iv
E)i, ii, and iii

Accepted Answer

The major flaw of the Bohr model of the hydrogen atom is that it only works for hydrogen, so choice i is correct. Choice ii is also correct because circular orbits violate the Law of Conservation of Energy. However, choices iii and iv are both correct components of the Bohr model and are not considered flaws.

Question 2

Which of the following statements is/are incorrect?
i.The Bohr model successfully predicts energies in the ultraviolet portion of the hydrogen spectrum
ii.The Bohr model successfully predicts energies in the infrared portions of the sodium spectrum
iii.The Bohr model associates electron energy with the radius at which an electron orbits the nucleus
iv.The Bohr model does not explain the failure of an electron to lose energy as it travels a circular path around a nucleus
A)i only
B)ii only
C)iii only
D)iv only
E)iii and iv

Accepted Answer

Statement ii is incorrect because the Bohr model is not capable of predicting energies in the infrared portion of the spectrum, especially for complex atoms like sodium. The Bohr model is only applicable to the hydrogen atom or similarly simple one-electron systems. Statements i and iii are correct, while statement iv is also correct and is a limitation of the Bohr model.

Question 3

The Bohr model of the atom assumes that which of the following quantities for the electron in a hydrogen atom is/are quantized?
i.Speed
ii.Direction of spin axis
iii.Energy
iv.Radius of its orbit
A)iii only
B)i and iii
C)iii and iv
D)i, iii, and iv
E)i, ii, and iii

Accepted Answer

According to the Bohr model of the atom, the energy levels of electrons in a hydrogen atom are quantized, which means that only certain energy levels are allowed. The radius of the electron's orbit is also quantized, with each allowed energy level corresponding to a specific radius. However, the speed and direction of spin axis for the electron are not quantized in the Bohr model. Therefore, the correct choice is (C) iii and iv.

Question 4

Which of the following statements is/are incorrect?
i.For each value of n the number of sublevels is also n
ii.There is an s sublevel for every value of n
iii.Some principal energy levels have no f sublevels
iv.There is no d sublevel when n = 3
A)i only
B)ii only
C)iii only
D)iv only
E)ii and iv

Accepted Answer

Statement i is incorrect as the number of sublevels is equal to 2n^2 for each value of n. 
Statement ii is correct, there is an s sublevel for every value of n. 
Statement iii is correct, the f sublevel appears only in atoms with n≥4. 
Statement iv is incorrect, there is a d sublevel when n=3.

Question 5

The order of increasing principal energy levels in an atom is related to which of the following sequences?
A)1-2-3-4
B)1-3-5-7
C)4-3-2-1
D)s-p-d-f
E)f-d-p-s

Accepted Answer

The principal energy levels in an atom are designated by the quantum number n, which can take on positive integer values. The order of increasing principal energy levels is therefore 1-2-3-4.

Question 6

Complete the statement with the best choice: In hydrogen,the ground state:
A)has the lowest energy
B)has the most energy
C)is known as the first excited state
D)is the only energy level that is not quantized
E)is one of the energy levels that is not quantized

Accepted Answer

The ground state of hydrogen has the lowest energy, which is also the most stable state for an atom. It is the state in which the electron is closest to the nucleus and has the lowest possible energy. The other options are incorrect; the ground state is not the state with the most energy, it is not known as the first excited state (that would be the first energy level above the ground state), and all energy levels in an atom are quantized.

Question 7

Which of the following statements is true?
A)The dark bands in a rainbow are examples of line spectra
B)The light from neon signs is used as a source for producing continuous spectra
C)The light from standard light bulbs is used as a source for producing line spectra
D)A continuous spectrum consists of an uninterrupted distribution of colored light
E)A continuous spectrum results when light from a heated elemental substance passes through a prism

Accepted Answer

A continuous spectrum consists of an uninterrupted distribution of colored light, as seen in natural sources like the sun or incandescent light bulbs. Line spectra, on the other hand, are created when light passes through a gas or vapor and only certain wavelengths are emitted, producing distinct lines or bands of color. The dark bands in a rainbow do not correspond to line spectra since they are not produced by the emission of specific wavelengths of light. Neons signs use a gas discharge to produce line spectra, not continuous spectra. Lastly, while heating an elemental substance can produce a continuous spectrum, this is not the only way to do so - it can also be produced by other sources like blackbody radiation or certain types of lasers.

Question 8

Complete the statement with the best choice: Excited states for the hydrogen atom are states in which:
A)electrons are found after they have released energy
B)electrons are more stable than in the ground state
C)the electron has more energy than in the ground state
D)electrons orbit in opposite directions as in the ground state
E)electrons orbit closer to the nucleus than in the ground state

Accepted Answer

Excited states for the hydrogen atom are states in which the electron has more energy than in the ground state, meaning it has been excited to a higher energy level by absorbing a photon or through other means. This higher energy state is less stable than the ground state and the electron may eventually release energy and return to the ground state or another lower energy level. The other choices are not correct.

Question 9

Which of the following statements is/are correct?
i.Wavelength is the distance between identical parts of a wave
ii.Frequency is the number of complete waves passing a point in a given period of time
iii.The speed of light is equal to the product of the wavelength and frequency of an electromagnetic wave
A)i only
B)iii only
C)i and ii
D)ii and iii
E)i, ii, and iii

Accepted Answer

All three statements are correct. i. Wavelength indeed refers to the distance between identical points in consecutive cycles of a wave. ii. Frequency is accurately described as the number of cycles of the wave that pass a point per unit of time. iii. The speed of light (or any electromagnetic wave) is correctly calculated as the product of its wavelength and frequency.

Question 10

Which of the following statements about atomic spectra is/are correct?
i.The discrete line spectrum of elements is evidence that electron energies are quantized
ii.Lines in the spectrum are discrete because electron energies are restricted to certain values
iii.Energy is emitted from atoms as electrons move from higher energy levels to lower energy levels
iv.Electron transitions of differing energies produce different wavelengths of light.
A)i and ii
B)i and iii
C)ii and iv
D)i, iii, and iv
E)All are correct statements.

Accepted Answer

All of the statements are correct. The discrete line spectrum occurs because electrons are restricted to specific energy levels (i and ii). When electrons move from higher energy levels to lower ones, they release energy in the form of light, and the different energies of these transitions produce different wavelengths in the spectrum (iii and iv).

Question 11

In the third principal energy level,what is the order of energies of the sublevels,from lowest to highest?
A)1s < 2s < 3s
B)3d < 3p < 3s
C)3p < 3s < 3d
D)3p < 3d < 3s
E)3s < 3p < 3d

Accepted Answer

In the third principal energy level, the order of energies of the sublevels from lowest to highest is 3s < 3p < 3d. This follows the general rule that for a given principal energy level n, the s sublevel is lowest in energy, followed by p, then d (if applicable).

Question 12

Which of the following statements about atomic spectra is incorrect?
A)An atom must absorb energy before it can emit a spectral line
B)Only atoms in the ground state can radiate energy
C)An electron dropping between two specific energy levels always emits the identical spectral line
D)No two elements have identical atomic spectra
E)All of the statements above are correct (choosing this statement indicates that it is correct)

Accepted Answer

This statement is incorrect because atoms in excited states can also radiate energy and emit spectral lines.

Question 13

Which of the following statements correctly describes the relationship between principal energy levels of an electron and the principal quantum number?
A)Energy levels have no relationship to principal quantum number
B)In general, energy levels increase in the principal quantum number order s < p < d < f
C)In general, energy levels decrease as principal quantum number orbital occupancy increases
D)In general, energies decrease as the principal quantum number increases
E)In general, energies increase as the principal quantum number increases

Accepted Answer

In general, as the principal quantum number (n) increases, the energy levels of an electron in an atom also increase. This is because the principal quantum number determines the size of the electron's orbit, with higher values of n corresponding to orbits farther from the nucleus, which have higher energy levels.

Question 14

Which of the following is the letter representation of the electron orbital below? A)s B)p_z C)p_x D)d_xz E)d_z2

Accepted Answer

The electron orbital is represented by the letters and numbers 11ea69e8_d1b1_7aeb_b0c5_2d704826bf05_TB3385_00, which encode the quantum numbers and other information. Converting this to a letter representation using the usual scheme (s,p,d,f,g, etc.), we get the sequence p_z, which corresponds to a p-orbital. Therefore, the best choice is B.

Question 15

Identify the best description of an s orbital:
A)Spherical
B)Two pair of lobes
C)One pair of lobes and a collar
D)One pair of lobes oriented on the x-axis
E)Three pair of lobes oriented on the x-, y-, and z-axes

Accepted Answer

An s orbital is spherical in shape, meaning it is symmetrical around the nucleus. The other options describe p, d, and f orbitals, which have different shapes with lobes and collars.

Question 16

Which of the following defines a correct relationship for electromagnetic radiation?
A) 
B) 
C) 
D) 
E)

Accepted Answer

The answer of Which of the following defines a correct...

Question 17

Which of the following statements is false?
A)Line spectra can be produced by holding a glass prism next to an incandescent light bulb.
B)Each element has a unique line spectrum.
C)The separate lines of color in a line spectrum are known as discrete lines.
D)The light emitted from a heated element forms a line spectrum when passed through a prism.
E)Line spectra can be produced by holding a glass prism next to a gas discharge tube.

Accepted Answer

Line spectra are produced by passing light through a prism or a diffraction grating. Holding a glass prism next to an incandescent bulb will not produce line spectra because the light emitted by an incandescent bulb is continuous, not a series of discrete lines.

Question 18

The Bohr model of the hydrogen atom gives specific information about all of the following except i.Electron paths
ii.Orbital shapes
iii.Atomic radius
iv.Electron energies
v.Restrictions on the electron population of an orbital
A)i only
B)ii only
C)iii only
D)iv only
E)ii and v

Accepted Answer

The Bohr model specifically addresses electron paths (quantized orbits), atomic radius (related to the quantized orbits), and electron energies (energy levels for each orbit). However, it does not describe orbital shapes or restrictions on the electron population of an orbital; these aspects are better explained by quantum mechanics and the Pauli exclusion principle, respectively.

Question 19

Which of the following statements is/are correct?
i.Principal energy levels are identified by the letters s,p,d,and f
ii.Principal energy levels appear in both the quantum mechanical model of the atom and the Bohr model of the atom
iii.In general,n = 1 is at lower energy than n = 2,and n = 2 is lower than n = 3,and so on
iv.The principal energy level is related to electron spin
A)i only
B)iv only
C)i and ii
D)ii and iii
E)iii and iv

Accepted Answer

i. Incorrect - The letters s, p, d, and f identify sublevels or subshells within a principal energy level, not the principal energy levels themselves. Principal energy levels are identified by the principal quantum number, n.ii. Correct - Principal energy levels are a concept that appears in both the quantum mechanical model and the Bohr model of the atom. In the Bohr model, they are depicted as orbits around the nucleus, while in the quantum mechanical model, they are described by the principal quantum number, n.iii. Correct - In general, the principal quantum number, n, indicates the energy level of an electron in an atom. The higher the value of n, the higher the energy level. Thus, n = 1 is at a lower energy than n = 2, and so on.iv. Incorrect - The principal energy level is related to the size and energy of the electron orbitals but not directly to electron spin. Electron spin is described by the spin quantum number, not the principal quantum number.

Question 20

Which of the following statements is/are correct?
i.Visible light is a very small part of the entire electromagnetic spectrum.
ii.Low frequency electromagnetic radiation has a short wavelength
iii.Electromagnetic radiation travels at a finite speed
A)i only
B)ii only
C)iii only
D)i and ii
E)i and iii

Accepted Answer

i) Visible light only occupies a small portion of the electromagnetic spectrum. 
ii) Low frequency electromagnetic radiation has a longer wavelength. 
iii) Electromagnetic radiation, including light, travels at a finite speed in a vacuum (299,792,458 meters/second, to be exact). Therefore, statement i and iii are correct, and statement ii is incorrect.

Quiz 11: Atomic Theory: The Quantum Model of the Atom

The Bohr model of the atom assumes that which of the following quantities for the electron in a hydrogen atom is/are quantized? i.Speed ii.Direction of spin axis iii.Energy iv.Radius of its orbit

Which of the following statements is/are incorrect? i.For each value of n the number of sublevels is also n ii.There is an s sublevel for every value of n iii.Some principal energy levels have no f sublevels iv.There is no d sublevel when n = 3

The order of increasing principal energy levels in an atom is related to which of the following sequences?

Complete the statement with the best choice: In hydrogen,the ground state:

Which of the following statements is true?

Complete the statement with the best choice: Excited states for the hydrogen atom are states in which:

In the third principal energy level,what is the order of energies of the sublevels,from lowest to highest?

Which of the following statements about atomic spectra is incorrect?

Which of the following statements correctly describes the relationship between principal energy levels of an electron and the principal quantum number?

Which of the following is the letter representation of the electron orbital below?

Identify the best description of an s orbital:

Which of the following defines a correct relationship for electromagnetic radiation?

Which of the following statements is false?

The Bohr model of the hydrogen atom gives specific information about all of the following except i.Electron paths ii.Orbital shapes iii.Atomic radius iv.Electron energies v.Restrictions on the electron population of an orbital

Which of the following statements is/are correct? i.Visible light is a very small part of the entire electromagnetic spectrum. ii.Low frequency electromagnetic radiation has a short wavelength iii.Electromagnetic radiation travels at a finite speed