PSC 1121 - Chapter 8 (Atoms and Periodic Properties)
Select all that apply Rutherford's gold foil experiment was very important in developing the nuclear model of the atom. Which of the following statements correctly describe the observations made and the implications of each for atomic structure?
- A few alpha particles showed major deflections, and some were reflected, indicating the presence of a dense, positive core. - Most alpha particles passed straight through the foil, implying that the atom consists largely of empty space.
Select all that apply Which of the following statements correctly describe wave-particle duality?
- All matter exhibits wavelike motion. - Large objects have wavelengths that are too small to be detected or measured.
Match the tenet from Bohr's model of the hydrogen atom with its explanation.
- Allowed orbits --- Electrons can only exist in certain orbits. - Radiationless orbits --- Electrons do not emit light in their allowed orbits. - Quantum leaps --- Electrons move between orbits by absorbing or emitting exactly the energy difference between the two orbits.
Select all that apply Which of the following statements correctly describe the Bohr model?
- An electron in an allowed orbit does not emit radiant energy as long as it remains in the orbit. - An electron can only exist in fixed orbits around the nucleus.
Select all that apply What two pieces of information must be known to calculate the atomic weight of a particular element?
- Atomic mass of each isotope - Relative abundance of each isotope
Select all that apply Which of the following statements can be attributed to the quantum mechanical model of the atom?
- Electrons occupy a three-dimensional space near the nucleus. - The wave nature of the electron is emphasized.
Match each variable with its meaning in the equation developed by Bohr: En = E1/n2�1�2.
- En --- Energy of a particular orbit - E1 ---- Energy of the innermost orbit - n ---- Quantum number for an orbit
Select all that apply Select all the statements that accurately characterize the quantum mechanics theory of the atom.
- It considers the wave nature of electrons. - It states where electrons might be found, rather than where they definitely are.
Select all that apply Which of the following statements correctly describe the properties of a photon?
- Matter cannot absorb or emit a fraction of a photon. - Photons are discrete units of light energy.
Matching Question Match each component of an atom with the correct description.
- Nucleus ---Small, dense, positively charged region of the atom - Electron --- Negatively charged particle found outside of the nucleus - Proton --- Positively charged particle found within the center of the atom - Neutron --- Uncharged particle found within the center of the atom
Select all that apply Which of the following statements correctly describe an orbital?
- Orbitals have characteristic shapes and sizes. - An orbital defines the probability of finding an electron in a given region of an atom.
Select all that apply What are the problems with the solar system model of the atom?
- Orbiting electrons would accelerate. - The solar system model of the atom describes a situation in which the atom would collapse. - Orbiting electrons would emit light.
Select all that apply What are the problems with the solar system model of the atom?
- Orbiting electrons would emit light. - Orbiting electrons would accelerate. - The solar system model of the atom describes a situation in which the atom would collapse.
Match each quantum number with its meaning.
- Principal quantum number --- Main energy level of the electron - Angular momentum quantum number --- Energy sublevel - Magnetic quantum number --- Orientation in space - Spin quantum number --- Direction of spin
Match the description of electrons in an atom with the correct model.
- Quantum mechanical model --- Electrons occupy a three-dimensional space near the nucleus. - Bohr model --- Electrons occupy simple circular orbits that surround the nucleus.
Select all that apply Which of the following statements about the angular momentum quantum number is true?
- The angular momentum quantum number defines energy sublevels within the main energy levels. - The angular momentum quantum number defines energy sublevels with specific letter.
Select all that apply Which of the following statements correctly describe cathode rays?
- The discovery of cathode rays showed that an atom can be broken down into smaller particles. - A cathode ray consists of negatively charged particles. - Cathode rays are identical no matter what their source.
Select all that apply A particular isotope of an element is represented by the symbol ⁷⁹35Br. Which of the following options correctly interpret this symbol?
- The element contains 44 neutrons in the nucleus. - The element contains 35 protons in the nucleus. REASON: 79-35=44
Select all that apply Which of the following statements correctly describe electronic transitions in an atom?
- The energy absorbed or emitted in an electronic transition is exactly equal to the energy difference between the two orbits. - An electron absorbs energy to move to a higher-energy orbit.
elect all that apply Which of the following correctly describe the current model of the atom?
- The nucleus is a very small fraction of the total volume of the atom. - The mass of the atom is mostly the mass of the neutrons and protons. - The number of protons equals the number of electrons in a neutral atom.
Match each of the following experiments/observations with the information it contributed to the nuclear model of the atom. Instructions
- Thomson's experiment with cathode rays---The discovery of the electron - Millikan's oil-drop experiment--- The determination of the charge on a single electron - Rutherford's metal-foil experiment ---- The discovery of the nucleus of the atom
Select all that apply Which of the following statements about line spectra of atoms (pictured) in the gas phase is true?
-Atoms in the gas phase only emit radiation at certain frequencies. -Each atom has a characteristic line spectrum. -Each line in a line spectrum represents a specific energy.
Select all that apply Which of the following properties are described by the angular momentum, principal, spin, and magnetic quantum numbers?
-Direction of spin -Orientation in space -Energy
Select all that apply Which of the following properties are described by the angular momentum, principal, spin, and magnetic quantum numbers?
-Orientation in space -Energy -Direction of spin
Select all that apply Which of the following statements correctly describe the principal quantum number n?
-The n describes the distance of the electron from the nucleus. -The n can have any whole-number value.
Click and drag on elements in order Rank the energy sublevels from lowest to highest energy. Place the sublevel with the lowest energy at the top of the list and the sublevel with the highest energy at the bottom.
1. S 2. p 3. d 4. f
calculate the de Broglie wavelength of a 1.67 x 10-27 kg neutron with a velocity of 2.70 x 108 m/s. λ = hmvℎmv and h = 6.63 x 10-34 J⋅s and J = kg⋅m²s²kg⋅�²�².
1.47 x 10-15 m Reason:Reason: λ = 6.626x10−34J⋅s/(1.67x10−27kg)(2.70x108m/s)= 1.47 x 10-15 m
What is the energy of a photon of light with a frequency of 5.4 x 1015 Hz? (h = 6.63 x 10-34 J⋅s)?
3.6 x 10-18 J
What is the wavelength of the violet line (n = 6) in the hydrogen line spectra according to Balmer's equation? Blank______ x 10-7 m 1λ1λ = R(122122 - 1n²1�²) where R = 1.097 x 107 1/m
4.1
What is the wavelength of the violet line (n = 6) in the hydrogen line spectra according to Balmer's equation? Blank______ x 10-7 m 1λ1λ = R(122122 - 1n²1�²) where R = 1.097 x 10^7 1/m
4.1 Reason: 1λ1λ = 1.09 x 107 1m1�(122122 - 162162) = 2.44 x 106 1m1� λ = 4.10 x 10-7 m
An unknown element has two primary isotopes, one with a relative abundance of 25.34 percent and a mass of 52.35 u, and another with a relative abundance of 74.66 percent and a mass of 54.87 u. What is the atomic weight of this element?
54.23 u Reason: (0.2534 x 52.35 u) + (0.7466 x 54.87 u) = 54.23 u
Calculate the wavelength of the red line (n = 3) in the hydrogen line spectra according to Balmer's equation. 1λ1λ = R(122122 - 1n²1�²) where R = 1.097 x 107 1/m
6.6 x 10-7 m Reason: 1/λ = 1.09 x 107 1m1�(122122 - 132132) = 1.52 x 106 1m1� λ = 6.6 x 10-7 m
Calculate the wavelength of the red line (n = 3) in the hydrogen line spectra according to Balmer's equation. 1λ1λ = R(122122 - 1n²1�²) where R = 1.097 x 107 1/m
6.6 x 10^-7 m
Select all that apply Which of the following statements correctly describe wave-particle duality?
All matter exhibits wavelike motion. De Broglie deduced that particle and wave properties can be related through the equation λ = h/mv.
What is the correct definition of atomic weight?
Atomic weight is the weighted average, relative to carbon-12, of all naturally occurring isotopes for a given element.
An unknown element has two primary isotopes, one with a relative abundance of 99.63 percent and a mass of 14.00307 u, and another with a relative abundance of 0.37 percent and a mass of 15.0011 u. What is the atomic weight of this element? ________________ u (Give your answer to 2 decimal places.)
Blank 1: 14.00 or 14.01
What is the frequency of the energy emitted when the electron of a hydrogen atom moves from the n = 1 to the n = 2 energy level? (Round the answer to two decimal places.), __________ x 1015 Hz
Blank 1: 2.47
WORK PROBLEM: The energy of a photon of light with a frequency of 4.3 x 1014 Hz is _____________ x 10-19 J. Note: h = 6.63 x 10-34 J⋅s. (Report your answer to two decimal places.)
Blank 1: 2.85 Reason: Example 8.1
What is the wavelength associated with a 0.43 kg soccer ball that is kicked at a velocity of 25 m/s? λ = hmvℎmv and h = 6.63 x 10-34 J⋅s and J = kg⋅m²s²kg⋅�²�² _________ x 10-35 m (Provide an answer with 3 significant figures.)
Blank 1: 6.17 or 6.167
The four lines that make up the visible region of the line spectra of hydrogen became known as the ____________ series, named after the person who developed an equation to determine the wavelength of each line.
Blank 1: Balmer
Rutherford's famous gold-foil experiment tracked the location of ______________ particle impacts on a thin metal foil in order to understand the nature of radioactivity.
Blank 1: alpha
Equal to 1/12 the mass of a carbon-12 atom, the __________ ____________ ____________ is used to describe the relative mass of an atom.
Blank 1: atomic Blank 2: mass Blank 3: unit
The energy of an electron moving through a potential of 1 volt is called a(n) ____________ _______________ (eV).
Blank 1: electron Blank 2: volt
The principal quantum number is given the symbol __________ and has positive, whole-number values starting with ___________.
Blank 1: n Blank 2: 1 or one
n the solar system model of the atom, the is the _________ Sun and the __________ are the planets. The electrical attractions between these species act as the _____________ attraction.
Blank 1: nucleus Blank 2: electrons Blank 3: gravitational or gravity
An atom is composed of a very dense central ____________ containing ____________ , which are positively charged, and neutrons, which have ____________ electric charge.
Blank 1: nucleus or core Blank 2: protons Blank 3: no, zero, 0, or neutral
Albert Einstein stated that light follows the quantum concept proposed by Planck and consists of discrete units of energy called _____________.
Blank 1: photons
The Heisenberg uncertainty principle states that it is not possible to know the exact momentum and ____________ of an electron simultaneously. In terms of atomic structure, this means that we cannot determine fixed orbits for electrons but can only determine the ____________ of finding an electron in a given region of space.
Blank 1: position or location Blank 2: probability, possibility, or probabilities
The Heisenberg uncertainty principle states that it is not possible to know the exact momentum and _____________ of an electron simultaneously. In terms of atomic structure, this means that we cannot determine fixed orbits for electrons but can only determine the ________________ of finding an electron in a given region of space.
Blank 1: position or location Blank 2: probability, possibility, or probabilities
The discrete units of energy discovered by Planck are called ____________.
Blank 1: quanta
An orbital ______________ represents where an electron could probably be located at any particular instant.
Blank 1: shape
Louis de Broglie demonstrated that matter is similar to light in that it has properties characteristic of both _________ and particles. This theory helped to explain the anomalous behavior of __________ in an atom.
Blank 1: waves Blank 2: electrons
There were a few limitations of the Blank______ model of the atom, including no explanation for the quantized orbits and his rule of radiationless orbits.
Bohr
Which of the following equations correctly reflects the relationship between energy and frequency?
E = hf Reason: A quantum of energy (E) is equal to Planck's constant (h) multiplied by the frequency (f) of light.
Which statement correctly describes what occurs when the electron of the hydrogen atom moves from the n = 1 to the n = 3 energy level? Use the provided energy level diagram of hydrogen to answer this question.
Energy with a frequency of 2.92 x 1015 Hz is absorbed by the atom.
Which of the following statements correctly describes isotopes?
Isotopes have different numbers of neutrons.
What is a consequence of the Heisenberg uncertainty principle?
It is not possible to assign an electron to a fixed orbit.
A particular isotope of an element is represented by the symbol 8 15 O . Match the correct term with the correct number.
Mass number --- 15 Number of protons --- 8 Number of neutrons --- 7
Select all that apply Which of the following statements correctly describe the observations that led to the development of the nuclear model of the atom?
Rutherford determined that the mass of an atom is concentrated in the central region. Thomson measured the charge-to-mass ratio for an electron.
What do scientists mean when they describe light as having a wave-particle duality?
That light is both a wave and a particle simultaneously correct Reason: Yes, light is both at the same time, but we normally can measure one aspect of it at a time.
What is the limitation of the Bohr model of the atom?
The Bohr model cannot account for the behavior of multielectron species.
What does the Bohr equation (shown) allow one to calculate? En =E1/n2
The allowed energies of each of the orbits correct Reason: Bohr found that the energy of each of the allowed orbits could be found from the simple relationship of equation En =E1n2�� =�1�2.
Select all that apply Which of the following statements correctly describe the atomic number of an element?
The atomic number is equal to the number of protons in the nucleus. Each element has its own unique atomic number.
Select all that apply Which of the following statements correctly describe subatomic particles?
The electrons are located outside the nucleus of an atom. The mass of an electron is negligible compared to the mass of a proton.
What is an electron volt?
The energy of an electron moving through a potential of 1 V
What does the equation based on the Bohr model of the atom (shown) allow one to calculate? hf = EH − EL
The energy that is emitted or absorbed when the hydrogen electron moves between energy states
Which of the following defines the ground state of an atom?
The lowest energy state
Select all that apply Which of the following statements correctly describe the mass number of an element?
The mass number is given by the sum of the protons and neutrons in the nucleus. The mass number is often written as a left superscript next to the chemical symbol.
True or false: Line spectra of atoms in the gas phase do not show a continuous spread of frequencies.
True Reason: Line spectra of atoms only show lines of colors at certain frequencies.
True or false: Line spectra of atoms in the gas phase do not show a continuous spread of frequencies.
Truecorrect Reason: Line spectra of atoms only show lines of colors at certain frequencies.
When is the potential energy of an electron considered to be zero?
When the electron is removed from the atom
An electron moves to a higher-energy orbit by Blank______ energy from high temperatures or electrical discharges and moves to a lower-energy orbit by Blank______ energy in the form of light. The energy absorbed or emitted must exactly equal the energy Blank______ between the two orbits.
absorbing; emitting; difference
Isotopes are atoms of the same element that have the same Blank______ number but a different Blank______ number. This is because isotopes have the same number of protons but a different number of Blank______.
atomic; mass; neutrons
All atomic masses are determined relative to a(n) Blank______-12 standard; this isotope is defined to be exactly 12 atomic mass units (u).
carbon
According to the equation, E = hf, the energy of a photon is Blank______ proportional to the frequency of radiation, where h is a proportionality constant known as Blank______ constant and f is the frequency of radiation.
directly; Planck's
Quanta are Blank______
discrete packets of energy
The angular momentum quantum number describes Blank______. Each of these is identified with a Blank______.
energy sublevels; letter
The number of possible sublevels for each main energy level is Blank_________ the principal quantum number.
equal to
The quantum mechanics model describes the location of electrons as Blank______.
fuzzy statistical representations
An electron in the Blank______ state will jump to a(n) Blank______ state when it absorbs a quantum that is equal to the difference in energy between the two states.
ground; excited
Match the variable with its meaning in the equation shown. hf = EH − EL�H - �L Instructions
h --- Planck's constant f --- Frequency EH --- Energy of the orbit farthest from the nucleus EL --- Energy of the orbit closest to the nucleus
The Blank______ number of an atom is the sum of its protons and Blank______.
mass; neutrons
In Rutherford's gold-foil experiment, he observed that most of the alpha particles passed straight through the foil, indicating that the atom is Blank______. Some alpha particles were deflected at large angles, and others were reflected back toward the source, which caused him to conclude that the atom contains a dense, Blank______ charged nucleus surrounded by electrons.
mostly empty space; positively
Match each principal quantum number with the correct number of sublevels associated with it.
n = 1 ---- 1 n = 2 --- 2 n = 3 --- 3 n = 4 --- 4
Thomson discovered that cathode rays emanate from the Blank______ electrode. This among other experimental evidence caused him to postulate that they consist of particles of the same charge. However, the major breakthrough made by Thomson was that the charge-to-mass ratio of the particles that make up cathode rays are Blank______ for each source.
negative; the same
When an electron is in the orbit closest to the nucleus, its value for potential energy will be Blank______. When an electron is completely removed from the nucleus, its potential energy is Blank______.
negative; zero
The magnetic quantum number indicates the Blank______ of an orbital in space.
orientation
Select all that apply Which of the following are letters associated with energy sublevels in an atom?
p d f (HIGHEST SUBLEVEL) s (LOWEST LEVEL)
The atomic number of each element is unique and represents the number of Blank______ in the nucleus. Since an atom is neutral, this number is also equal to the number of Blank______ present.
protons; electrons
Balmer developed an equation based on the Blank______ line spectrum of the element Blank______. His equation allowed him to directly calculate the Blank______ of each line in the line spectrum.
visible; hydrogen; wavelength
All matter behaves as though it moves as a Blank______. The motion of any particle can be described by the de Broglie equation, which relates wavelength of a particle to its Blank______ and speed.
wave; mass
Match the variable with the correct term from the de Broglie equation: λ = h/mv
λ --- wavelength h --- Planck's constant m --- mass v ---- velocity
Select all that apply Which of the following statements correctly describe the mass number of an element?
•The mass number is often written as a left script next to the chemical symbol. •The mass number is given by the sum of the protons and neutrons in the nucleus.
