Q: A lightning strike is observed before its thunder is heard. Based on the properties of electromagnetic and sound waves, why does this occur?

Light waves travel at $$3.00 \times 10^8$ m/s, much faster than sound waves at 340 m/s.

Q: Which of the following best describes the relationship between wavelength ($$\lambda) $$and frequency ($$\nu) $$for electromagnetic waves?

Wavelength and frequency are inversely proportional: $$\nu = \frac{c}{\lambda}.$$

Question 1

Which of the following statements best explains why a rainbow displays multiple colors when sunlight passes through raindrops?

Accepted Answer

Raindrops act as prisms, dispersing sunlight into its component wavelengths, each corresponding to a different color.

Question 2

A lightning strike is observed before its thunder is heard. Based on the properties of electromagnetic and sound waves, why does this occur?

Accepted Answer

Light waves travel at $$3.00 	imes 10^8$ m/s, much faster than sound waves at 340 m/s.

Question 3

Which of the following best describes the relationship between wavelength ($$\lambda) $$and frequency ($$
u) $$for electromagnetic waves?

Accepted Answer

Wavelength and frequency are inversely proportional: $$
u = \frac{c}{\lambda}.$$

Question 4

A bright green laser and a dim red laser are compared. Which statement is correct?

Accepted Answer

The two lasers emit light of different frequencies, and the green laser has a greater amplitude.

Question 5

Which region of the electromagnetic spectrum has the highest energy photons?

Accepted Answer

Gamma rays

Question 6

What is the energy of a single photon of light with a wavelength of 400 nm? (Use $$h = 6.626 	imes 10$$^{-34}$$ J·s and c = 3.00$$ 	imes $$10^8 m/s)$$

Accepted Answer

$$4.97 	imes 10$$^{-19}$$ J

Question 7

Which of the following transitions in a hydrogen atom would emit a photon with the longest wavelength?

Accepted Answer

$$3p \rightarrow 2s$$

Question 8

According to the quantum mechanical model, which set of quantum numbers is NOT allowed?

Accepted Answer

$$n=2,\ l=2,\ m_l=0$$

Question 9

Which statement about the photoelectric effect is correct?

Accepted Answer

Electrons are ejected only if the light's frequency is above a threshold, regardless of intensity.

Question 10

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

Angular momentum quantum number ($$l)$$

Question 11

How many orbitals are present in the $$n=3$$ principal energy level?

Accepted Answer

9

Question 12

Which of the following best describes the Heisenberg uncertainty principle?

Accepted Answer

The product of the uncertainties in position and momentum is always greater than $$\frac{h}{4\pi}.$$

Question 13

Which of the following is true about the emission spectrum of an element?

Accepted Answer

It is unique to each element and consists of discrete lines.

Question 14

What is the maximum number of electrons that can occupy the $$3d$$ sublevel?

Accepted Answer

10

Question 15

Which of the following best describes constructive interference?

Accepted Answer

Waves interact so that their amplitudes add together, producing a larger wave.

Question 16

A photon has an energy of $$3.31 	imes 10$$^{-19}$$ J. What is its frequency? (h = 6.626$$ 	imes $$10^{-34} J$$·s)

Accepted Answer

$$2.00 	imes 10$$^{15}$$ Hz

Question 17

Which of the following is a correct statement about the $$l=2$$ sublevel?

Accepted Answer

It is called the d sublevel and contains five orbitals.

Question 18

Which quantum number(s) determine the orientation of an orbital in space?

Accepted Answer

Magnetic quantum number ($$m_l)$$

Question 19

Which of the following best describes the difference between an s orbital and a p orbital?

Accepted Answer

An s orbital is spherical, while a p orbital is dumbbell-shaped.

Question 20

Which equation correctly relates the energy of a photon to its wavelength?

Accepted Answer

$$E = \frac{hc}{\lambda}$$

CHEM 131 Chapter 8: The Quantum-Mechanical Model of the Atom: Foundations, Light, and Atomic Structure

Study Guide - Practice Questions

Study Guide - Flashcards