Q: A laser emits green light with a wavelength of $$515\ \mathrm{nm}. $$What is the frequency of this light? (Speed of light $$c = 3.00 \times 10^8$\ \mathrm{m/s})$$

$$5.83 \times 10$$^{14}$$\ \mathrm{Hz}$$

Q: Calculate the energy of a single photon with a wavelength of $$337\ \mathrm{nm}$$. ($$h = 6.626 \times 10$$^{-34}$$\ \mathrm{J\cdot s}$$, $$c = 3.00 \times 10^8$\ \mathrm{m/s})$$

$$5.90 \times 10$$^{-19}$$\ \mathrm{J}$$

Q: What is the de Broglie wavelength of an electron (mass $$9.11 \times 10$$^{-31}$$\ \mathrm{kg}) $$traveling at $$2.65 \times 10^6$\ \mathrm{m/s}$$? ($$h = 6.626 \times 10$$^{-34}$$\ \mathrm{J\cdot s})$$

$$2.73 \times 10$$^{-10}$$\ \mathrm{m}$$

Question 1

Which of the following statements best describes the Heisenberg Uncertainty Principle?

Accepted Answer

The more precisely we know the position of a particle, the less precisely we can know its momentum.

Question 2

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

Accepted Answer

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

Question 3

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

Angular momentum quantum number, $$l$$

Question 4

Which of the following best explains why sodium metal emits electrons when exposed to ultraviolet light but not to visible light?

Accepted Answer

Ultraviolet photons have more energy than the binding energy of sodium's electrons.

Question 5

Calculate the energy of a single photon with a wavelength of $$337\ \mathrm{nm}$$. ($$h = 6.626 	imes 10$$^{-34}$$\ \mathrm{J\cdot s}$$, $$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

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

Question 6

Which of the following sets of quantum numbers is NOT allowed?

Accepted Answer

$$n = 4,\ l = 1,\ m_l = -2$$

Question 7

Which principle states that no two electrons in an atom can have the same set of four quantum numbers?

Accepted Answer

Pauli Exclusion Principle

Question 8

Arrange the following types of electromagnetic radiation in order of increasing energy per photon: microwaves, visible light, X-rays.

Accepted Answer

microwaves \u003c visible light \u003c X-rays

Question 9

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

Accepted Answer

Emission spectra have colored lines from electrons dropping to lower energy levels; absorption spectra have dark lines from electrons absorbing energy to move to higher levels.

Question 10

What is the de Broglie wavelength of an electron (mass $$9.11 	imes 10$$^{-31}$$\ \mathrm{kg}) $$traveling at $$2.65 	imes 10^6$\ \mathrm{m/s}$$? ($$h = 6.626 	imes 10$$^{-34}$$\ \mathrm{J\cdot s})$$

Accepted Answer

$$2.73 	imes 10$$^{-10}$$\ \mathrm{m}$$

Question 11

Which quantum number(s) determine the number of orbitals in a given principal energy level $$n$$?

Accepted Answer

$$n$$ and the number of orbitals is $$n^2$$

Question 12

Which of the following is a correct electron configuration for a ground-state neutral atom of calcium ($$Z=20$$)?

Accepted Answer

$$1s^22s^22$p^63s^23$p^64s^2$

Question 13

Which rule explains why electrons fill degenerate orbitals singly before pairing up?

Accepted Answer

Hund's Rule

Question 14

Which of the following best describes why the noble gases are chemically inert?

Accepted Answer

They have a full valence shell of electrons, making their electron configuration especially stable.

Question 15

Which of the following ions has the same electron configuration as argon ($$Z=18$$)?

Accepted Answer

$$\mathrm{K}^+$$

Question 16

Which of the following statements about the periodic trends in atomic radius is correct?

Accepted Answer

Atomic radius increases down a group and decreases across a period from left to right.

Question 17

A 100-watt lightbulb emits light at $$525\ \mathrm{nm}. $$How many photons are emitted per second? ($$h = 6.626 	imes 10$$^{-34}$$\ \mathrm{J\cdot s}$$, $$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$2.64 	imes 10$$^{20}$$

Question 18

Which of the following best describes the relationship between wavelength and frequency for electromagnetic waves?

Accepted Answer

They are inversely proportional.

Question 19

Which of the following is true about the electron configuration of chromium ($$Z=24$$)?

Accepted Answer

It is $$[\mathrm{Ar}]4s^13$d^5$$ due to increased stability of half-filled $$d$ subshell.

Quantum-Mechanical Model of the Atom: Study Guide

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