Q: A laser emits light with a wavelength of $$500\ \mathrm{nm}. $$What is the energy of a single photon from this laser? (Use $$h = 6.626 \times 10$$^{-34}$$\ \mathrm{J \cdot s}$$ and $$c = 3.00 \times 10^8$\ \mathrm{m/s})$$

$$3.98 \times 10$$^{-19}$$\ \mathrm{J}$$

Q: A sodium lamp emits yellow light with a frequency of $$5.09 \times 10$$^{14}$$\ \mathrm{Hz}. $$What is the energy of one photon of this light?

$$3.37 \times 10$$^{-19}$$\ \mathrm{J}$$

Question 1

Which of the following best describes the quantum-mechanical model of the atom?

Accepted Answer

It models electrons as exhibiting both wave-like and particle-like properties, with their behavior described by probability distributions.

Question 2

Which equation correctly relates the energy $$E of a $$photon to its frequency $$
u$$?

Accepted Answer

$$E = h 
u$$

Question 3

A laser emits light with a wavelength of $$500\ \mathrm{nm}. $$What is the energy of a single photon from this laser? (Use $$h = 6.626 	imes 10$$^{-34}$$\ \mathrm{J \cdot s}$$ and $$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$3.98 	imes 10$$^{-19}$$\ \mathrm{J}$$

Question 4

Which of the following statements about electromagnetic radiation is TRUE?

Accepted Answer

Energy increases as frequency increases.

Question 5

The photoelectric effect demonstrates which property of light?

Accepted Answer

Light can be described as a stream of particles called photons.

Question 6

Which equation gives the threshold frequency $$
u_0$ for the photoelectric effect, given the work function $$\phi$$?

Accepted Answer

$$
u_0$ = \frac{\phi}{h}$$

Question 7

Which quantum number determines the size of an atomic orbital?

Accepted Answer

Principal quantum number $$n$$

Question 8

An electron transitions from $$n=4 to$$ $$n=2 in a $$hydrogen atom. Which statement is correct?

Accepted Answer

The electron emits energy as a photon.

Question 9

Which formula calculates the energy difference $$\Delta E$$ between two energy levels $$n_1$$ and $$n_2 in a $$hydrogen atom?

Accepted Answer

$$\Delta E = -13.6 \left( \frac{1}{n_2$^2} - \frac{1}{n_1$^2} \right)\ \mathrm{eV}$$

Question 10

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

Accepted Answer

Magnetic quantum number $$m_l$$

Question 11

Which of the following best explains why electrons in atoms do not spiral into the nucleus?

Accepted Answer

Electrons occupy quantized energy levels, preventing continuous energy loss.

Question 12

Which quantum number is responsible for the shape of an orbital?

Accepted Answer

Angular momentum quantum number $$l$$

Question 13

A sodium lamp emits yellow light with a frequency of $$5.09 	imes 10$$^{14}$$\ \mathrm{Hz}. $$What is the energy of one photon of this light?

Accepted Answer

$$3.37 	imes 10$$^{-19}$$\ \mathrm{J}$$

Question 14

Which statement about the emission spectrum of hydrogen is correct?

Accepted Answer

It consists of discrete lines corresponding to specific electron transitions.

Question 15

Which quantum number can have values from $$-l to$$ $$+l$$?

Accepted Answer

Magnetic quantum number $$m_l$$

Question 16

Which of the following is a consequence of the wave-particle duality of electrons?

Accepted Answer

Electrons can exhibit interference and diffraction patterns.

Question 17

If the work function $$\phi of a $$metal is $$2.50\ \mathrm{eV}$$, what is the minimum frequency of light required to eject electrons from the metal? ($$h = 4.1357 	imes 10$$^{-15}$$\ \mathrm{eV \cdot s})$$

Accepted Answer

$$6.05 	imes 10$$^{14}$$\ \mathrm{Hz}$$

Question 18

Which quantum number is associated with electron spin?

Accepted Answer

Spin quantum number $$m_s$$

Question 19

Which of the following best describes the difference between absorption and emission spectra?

Accepted Answer

Absorption spectra show dark lines where light is absorbed; emission spectra show bright lines where light is emitted.

Question 20

Which principle explains why no two electrons in an atom can have the same set of quantum numbers?

Accepted Answer

Pauli exclusion principle

The Quantum-Mechanical Model of the Atom: Study Guide

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