Q: What is the energy of a photon with a wavelength of $$486\ \mathrm{nm}$$? (Planck's constant $$h = 6.626 \times 10$$^{-34}$$\ \mathrm{J\cdot s}$$, speed of light $$c = 3.00 \times 10^8$\ \mathrm{m/s})$$

$$4.09 \times 10$$^{-19}$$\ \mathrm{J}$$

Q: A photon of light has an energy of $$3.0 \times 10$$^{-19}$$\ \mathrm{J}. $$What is its frequency? ($$h = 6.626 \times 10$$^{-34}$$\ \mathrm{J\cdot s})$$

$$4.53 \times 10$$^{14}$$\ \mathrm{Hz}$$

Question 1

Which statement best describes the difference between classical mechanics and quantum mechanics in predicting the behavior of electrons in atoms?

Accepted Answer

Quantum mechanics predicts the probability distribution of electrons, while classical mechanics predicts definite paths.

Question 2

According to the de Broglie relation, what is the wavelength $$\lambda of an $$electron with mass $$m$$ and velocity $$v$$?

Accepted Answer

$$\lambda = \dfrac{h}{mv}$$

Question 3

Which of the following electromagnetic waves has the highest energy per photon?

Accepted Answer

X-rays

Question 4

A hydrogen atom undergoes a transition from $$n=3 to$$ $$n=2. $$What type of electromagnetic radiation is emitted?

Accepted Answer

Infrared

Question 5

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

Angular momentum quantum number ($$l)$$

Question 6

What is the maximum number of orbitals in the $$n=3$$ principal energy level?

Accepted Answer

9

Question 7

Which statement about the photoelectric effect is correct?

Accepted Answer

Electrons are emitted only if the light frequency exceeds a threshold value, regardless of intensity.

Question 8

If the frequency of red light is $$4.28 	imes 10$$^{14}$$\ \mathrm{Hz}$$, what is its wavelength in nanometers? (Speed of light $$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$701\ \mathrm{nm}$$

Question 9

Which of the following best explains why ultraviolet light can cause more biological damage than visible light?

Accepted Answer

Ultraviolet light has a shorter wavelength and higher energy per photon than visible light.

Question 10

Which set of quantum numbers is valid for an electron in a $$3d$$ orbital?

Accepted Answer

$$n=3,\ l=2,\ m_l=2$$

Question 11

According to Heisenberg's uncertainty principle, which statement is true?

Accepted Answer

The more precisely the position of an electron is known, the less precisely its momentum can be known.

Question 12

Which phenomenon provides evidence for the wave nature of electrons?

Accepted Answer

Electron diffraction

Question 13

What is the energy of a photon with a wavelength of $$486\ \mathrm{nm}$$? (Planck's constant $$h = 6.626 	imes 10$$^{-34}$$\ \mathrm{J\cdot s}$$, speed of light $$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$4.09 	imes 10$$^{-19}$$\ \mathrm{J}$$

Question 14

Which statement about atomic emission spectra is correct?

Accepted Answer

Emission spectra of elements consist of bright lines at specific wavelengths.

Question 15

What is the relationship between the energy and wavelength of electromagnetic radiation?

Accepted Answer

Energy is inversely proportional to wavelength.

Question 16

Which orbital has a spherical shape and no nodes?

Accepted Answer

1s

Question 17

A photon of light has an energy of $$3.0 	imes 10$$^{-19}$$\ \mathrm{J}. $$What is its frequency? ($$h = 6.626 	imes 10$$^{-34}$$\ \mathrm{J\cdot s})$$

Accepted Answer

$$4.53 	imes 10$$^{14}$$\ \mathrm{Hz}$$

Question 18

Which of the following best describes constructive interference?

Accepted Answer

Two waves of equal amplitude and in phase combine to produce a wave with greater amplitude.

Question 19

Which quantum number specifies the orientation of an orbital in space?

Accepted Answer

Magnetic quantum number ($$m_l)$$

Question 20

What is the total number of orbitals in the $$n=4$$ principal energy level?

Accepted Answer

16

Chapter 2: Quantum Theory

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