Q: A 100-watt light bulb emits light at a wavelength of 525 nm. How many photons are emitted per second? (Planck's constant $$h = 6.626 \times 10$$^{-34}$$ J·s, c = 3.00$$ \times $$10^8 m/s)$$

$$2.64 \times 10$$^{20}$$ photons/s

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

$$\lambda$$ and $$\nu$$ are inversely proportional: $$c = \lambda \nu$$

Question 1

Which of the following best describes the wave–particle duality of the electron?

Accepted Answer

Electrons exhibit both particle-like and wave-like properties depending on the experimental conditions.

Question 2

A green laser emits light with a wavelength of 515 nm. What is the frequency of this light? (Speed of light $$c = 3.00 	imes 10^8$ m/s)

Accepted Answer

$$5.83 	imes 10$$^{14}$$ Hz

Question 3

Which of the following statements about the photoelectric effect is correct?

Accepted Answer

Electrons are ejected from a metal surface only if the light has a frequency above a certain threshold, regardless of intensity.

Question 4

Arrange the following types of electromagnetic radiation in order of increasing wavelength: X-ray, visible, infrared.

Accepted Answer

X-ray \u003c visible \u003c infrared

Question 5

A 100-watt light bulb emits light at a wavelength of 525 nm. How many photons are emitted per second? (Planck's constant $$h = 6.626 	imes 10$$^{-34}$$ J·s, c = 3.00$$ 	imes $$10^8 m/s)$$

Accepted Answer

$$2.64 	imes 10$$^{20}$$ photons/s

Question 6

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

Angular momentum quantum number $$l$$

Question 7

According to the de Broglie relation, what happens to the wavelength of a particle as its momentum increases?

Accepted Answer

The wavelength decreases.

Question 8

Which of the following transitions in a hydrogen atom emits light with the highest energy?

Accepted Answer

$$n = 3 \rightarrow n = 2$$

Question 9

What is the energy of a single photon with a wavelength of 337 nm? (Use $$h = 6.626 	imes 10$$^{-34}$$ J·s, c = 3.00$$ 	imes $$10^8 m/s)$$

Accepted Answer

$$5.90 	imes 10$$^{-19}$$ J

Question 10

Which statement best summarizes Heisenberg’s uncertainty principle?

Accepted Answer

Either the position or the velocity of an electron can be accurately known at the same instant, but not both.

Question 11

How many possible values of the magnetic quantum number $$m_l$$ are there for $$l = 2$$?

Accepted Answer

5

Question 12

Which of the following best explains why we do not observe wave properties for a baseball thrown at a ballpark?

Accepted Answer

Because of the baseball’s large mass, its de Broglie wavelength is minuscule and insignificant compared to its size.

Question 13

Which quantum numbers are needed to uniquely describe a single electron in an atom?

Accepted Answer

Principal quantum number $$n$$, angular momentum quantum number $$l$$, magnetic quantum number $$m_l$$, and spin quantum number $$m_s$$

Question 14

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

Accepted Answer

16

Question 15

Which of the following is true about the emission spectrum of hydrogen?

Accepted Answer

It consists of discrete lines, each corresponding to a specific electron transition between energy levels.

Question 16

If an electron in a hydrogen atom transitions from $$n = 6 to$$ $$n = 5$$, what region of the electromagnetic spectrum does the emitted photon most likely fall into?

Accepted Answer

Infrared

Question 17

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

Accepted Answer

$$\lambda$$ and $$
u$$ are inversely proportional: $$c = \lambda 
u$$

Question 18

Which of the following is a correct statement about atomic orbitals?

Accepted Answer

An orbital is a probability distribution map describing where an electron is likely to be found.

Question 19

Which of the following best explains why ultraviolet light can eject electrons with greater kinetic energy than yellow light in the photoelectric effect?

Accepted Answer

Ultraviolet light has a higher frequency and therefore higher photon energy than yellow light.

Quantum Mechanics and Atomic Structure: Study Notes for General Chemistry

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