Question 1

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

Accepted Answer

Excited states for the hydrogen atom are states in which the electron has more energy than in the ground state. This is because an electron in the ground state has the lowest energy level, and as it absorbs energy, it can move to a higher energy level or excited state.

Question 2

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

Accepted Answer

B

Question 3

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

Accepted Answer

(i) Visible light is only a small part of the entire electromagnetic spectrum, which includes radio waves, microwaves, infrared radiation, ultraviolet radiation, X-rays, and gamma rays.
(ii) Frequency and wavelength are inversely proportional, meaning that low frequency electromagnetic radiation has a longer wavelength. High frequency radiation, such as X-rays, has a shorter wavelength.
(iii) Electromagnetic radiation travels at the speed of light, which is a finite speed, usually denoted by the symbol "c."

Question 4

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

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 5

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

Accepted Answer

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

Question 6

Which of the following statements about atomic spectra is incorrect?

Accepted Answer

Atoms in excited states can also radiate energy and emit spectral lines.

Question 7

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

Accepted Answer

Choice i is a flaw because the Bohr model only works for hydrogen and cannot explain the spectra of larger atoms. Choice ii is a flaw because circular orbits violate the Law of Conservation of Energy, as the electron would constantly emit radiation and lose energy, eventually collapsing into the nucleus. Choices iii and iv are not flaws but are actually strengths of the Bohr model, as it was able to explain atomic line spectra in terms of electron energies and introduced the idea of quantized electron energy levels in an atom, respectively.

Question 8

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

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 9

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

Accepted Answer

The answer of The order of increasing principal energy levels...

Question 10

Which of the following statements is true?

Accepted Answer

A continuous spectrum is a smooth and uninterrupted distribution of colored light, without any gaps or lines. This is commonly seen in sources of white light, such as the sun or incandescent light bulbs.

Question 11

Identify the best description of an s orbital:

Accepted Answer

An s orbital is a spherical-shaped region surrounding the nucleus where an electron is most likely to be found.

Question 12

Which of the following statements is false?

Accepted Answer

Line spectra cannot be produced by holding a glass prism next to an incandescent light bulb as the light emitted from an incandescent bulb produces a continuous spectrum rather than a discrete line spectrum.

Question 13

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

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 14

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

Accepted Answer

(i) is correct. 
(ii) is incorrect because the Bohr model was created specifically for hydrogen and does not apply to other elements. 
(iii) is correct. 
(iv) is incorrect because the Bohr model explains the stability of atoms by stating that electrons are in a quantized state and cannot lose energy as they move in circular orbits around the nucleus.

Question 15

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

Accepted Answer

The Bohr model of the atom assumes that both the energy and the radius of the electron's orbit are quantized. This means that they can only have specific, discrete values rather than any value in between. The speed and direction of spin axis of the electron are not quantized in the Bohr model. Therefore, the correct answer is (iii) and (iv).

Question 16

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.

Accepted Answer

All statements are correct. The discrete line spectrum is evidence of quantized energy levels for electrons in atoms. The lines in the spectrum are discrete because they correspond to specific energy transitions that electrons can make in the atom, and these transitions produce radiation with specific wavelengths. When electrons move from higher energy levels to lower ones, energy is emitted in the form of light, and these electron transitions of differing energies produce different wavelengths of light.

Question 17

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

Accepted Answer

The ground state of hydrogen is the lowest energy level that an electron can occupy. This is because electrons in atoms are restricted to certain energy levels, or quantized energy states. The ground state has the lowest energy and is the most stable configuration for the hydrogen atom.

Question 18

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

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 19

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

Accepted Answer

The statement "There is no d sublevel when n = 3" is incorrect. When n = 3, there is a d sublevel. All other statements are correct.

Question 20

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

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).

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