Deck 22: The Atomic Nucleus

Question 1

What are isobaric nuclides?

A)nuclei of the same element with different numbers of neutrons
B)nuclei of different elements with the same number of nucleons
C)nuclei of the same element with different numbers of protons
D)nuclei of different elements with the same number of protons

Answer 1

nuclei of different elements with the same number of nucleons

Question 2

What are isotopic nuclides?

A)nuclei of the same element with different numbers of neutrons
B)nuclei of different elements with the same number of nucleons
C)nuclei of the same element with different numbers of protons
D)nuclei of different elements with the same number of protons

Answer 2

nuclei of the same element with different numbers of neutrons

Question 3

Which of these particles is an alpha particle?

A)high energy photon
B)electron
C)positron
D)helium nucleus

Answer 3

helium nucleus

Question 4

How does the mass of an atomic nucleus compare with the sum of masses of its constituent nucleons separated?

A)The mass of a nucleus is larger than the sum of the masses of individual nucleons.
B)The mass of a nucleus is smaller than the sum of the masses of individual nucleons.
C)The mass of a nucleus is the same as the sum of the masses of individual nucleons.
D)The answer depends on the mass number of the element.

Question 5

What are the constituents of the atomic nucleus?

A)protons and neutrons
B)protons and electrons
C)photons and neutrons
D)positrons and neutrinos

Question 6

Which of these changes occurs in the nucleus during beta decay?

A)The mass number decreases by 4, and the atomic number decreases by 2.
B)The mass number does not change, but the atomic number changes.
C)The mass number changes, but the atomic number does not change.
D)Neither the mass number nor the atomic number changes.

Question 7

What is the mass number of an atomic nucleus equal to?

A)the number of protons
B)the number of neutrons
C)the number of protons and neutrons
D)the number of electrons

Question 8

How many neutrons are in the nucleus of carbon ¹⁴C?

A)6
B)7
C)8
D)14

Question 9

When an isomer decays, which of the following particles does it emit?

A)alpha particles
B)electrons
C)positrons
D)ã-photons

Question 10

How many protons are in the nucleus of oxygen ¹⁶O?

A)4
B)6
C)8
D)16

Question 11

Initially there are 6000 nuclei of an isotope with a half-life of 3 hours. How many nuclei of that isotope will be left after 12 hours?

A)375
B)750
C)1500
D)3000

Question 12

Which of these processes does NOT lead to the loss of a nucleon from a nucleus?

A)á-decay
B)â⁺-decay
C)â^--decay
D)electron capture

Question 13

What is the fraction of nuclei from the initial radioactive sample that have decayed after 3 half-lives?

A)7/8
B)3/4
C)1/2
D)1/8

Question 14

Which of these particles is a beta particle?

A)high energy photon
B)positron
C)helium atom
D)helium nucleus

Question 15

Which of these changes occurs in the nucleus during an alpha decay?

A)The mass number decreases by 4, and the atomic number decreases by 2.
B)The mass number does not change, but the atomic number changes.
C)The mass number changes, but the atomic number does not change.
D)Neither the mass number nor the atomic number changes.

Question 16

Which of these particles is emitted in gamma decay?

A)high energy photon
B)positron
C)helium atom
D)helium nucleus

Question 17

What is the atomic number of an atomic nucleus equal to?

A)the number of protons
B)the number of neutrons
C)the number of protons and neutrons
D)the number of electrons

Question 18

Which of these processes does NOT lead to a loss of charge in a nucleus?

A)alpha decay
B)beta decay
C)gamma decay
D)electron capture

Question 19

How many neutrons are in the nucleus of potassium ⁴⁰K?

A)20
B)21
C)22
D)40

Question 20

Which statement accurately describes the binding energy of a nucleus?

A)It is the difference between the masses of separated nucleons and the mass of a nucleus, converted into energy.
B)It is the energy required for a nucleus to bond nucleons.
C)It is equal to the mass of nucleons when converted into energy.
D)It is the difference between the mass of the atom and the mass of the electrons, converted into energy.

Question 21

Isotopic nuclides are nuclides with the same atomic number.

Question 22

The transition energy between two states of a spin- /2 nucleus in an external magnetic field is comparable to the Balmer series of electron transitions between energy states in the atom.

Question 23

A radioactive sample is left to decay for 4 half-lives. The fraction of the sample that decayed is 1/16.

Question 24

Using Table 22.1, calculate the energy released in the process of uranium decay: into

Question 25

Calculate the energy released in the process of decay of into [Note: 1 u = 931.5 MeV/c².]

Question 26

The Larmor frequency is the angular precession frequency of a nuclear spin in an external magnetic field.

Question 27

Which of the following is the Larmor frequency independent of?

A)the angle between the magnetic dipole moment of the nucleus and the external magnetic field
B)the magnitude of the external magnetic field for a specific nucleus
C)the gyromagnetic ratio
D)the magnetic dipole moment of the nucleus

Question 28

Nuclear force, like the electric force, acts only on charged particles. Neutrons are not affected by nuclear force.

Question 29

Using Table 22.1, compare the mass of ¹²C with the sum of masses of its constituent nucleons, in unit u.

Question 30

Isotopic nuclides are nuclides with the same mass number.

Question 31

Describe briefly an isomer. What is the difference between ¹²C^g and ¹²C^m?

Question 32

An isomer decays by emitting a gamma photon.

Question 33

Current loops act as magnetic dipoles.

Question 34

What is the maximal kinetic energy of an electron (â-particle) in the decay of sodium into magnesium?
[Note: + e^- + v.]

Question 35

Using Table 22.1, calculate the binding energy per nucleon of the ¹⁴C isotope.

Question 36

The activity of a radioactive sample is a positive or negative value of the decay rate, depending on the radioactive sample.

Question 37

The radioactive gas radon has a half-life of 3.8 days. How long will it take for the radon in a basement to decay to 50% of its present level?

A)1.9 days
B)3.8 days
C)7.6 days
D)16.4 days

Question 38

Electron capture is the equivalent of a beta radioactive decay.

Question 39

¹¹C, ¹²C, ¹³C, and ¹⁴C are examples of isobaric nuclides.

Question 40

The half-life is half the time needed for a radioactive sample to completely decay.

Question 41

Discuss briefly how transition energy, ÄE, between two states of a spin- /2 nucleus in an external magnetic field of 1 T (f = 50 MHz) compares to the Balmer series in a H atom, for example, the electron transition between n₂ and n₃ levels that involves a photon of wavelength ë = 655 nm.

Question 42

Describe briefly electron capture and its difference from and similarity to beta decay.

Question 43

A decay of into is an example of what type of a decay? What particle is released in the process?

Question 44

Calculate the strength of an NMR magnet if the Larmor frequency of protons in that field is 100 MHz. The gyromagnetic ratio for protons is ã/2ð = 42.58 MHz/T.

Question 45

What kind of decay is the decay of into and which particles are being emitted?

Question 46

A child mummy is found high in the Andes, and the archaeologists say that the child lived more than 2000 years ago. What is the fraction of found in the specimen compared to that found in a living body? The half-life of is 5700 years.

Question 47

What kind of decay is the decay of into and which particles are being emitted?