Question 1

Which of the following best describes the relationship between the radius $$R of a $$nucleus and its mass number $$A$$?

Accepted Answer

$$R is $$proportional to $$A^{1/3}$$

Question 2

A sample contains $$1.0 	imes 10^6$ radioactive atoms with a half-life of 3 days. How many atoms remain undecayed after 9 days?

Accepted Answer

$$1.0 	imes 10^5$

Question 3

Which of the following statements about the strong nuclear force is correct?

Accepted Answer

It is an attractive force between any two nucleons and is stronger than the electrostatic force at short distances.

Question 4

The binding energy per nucleon curve reaches its maximum at approximately which mass number $$A$$?

Accepted Answer

$$A \approx 56$$

Question 5

Which of the following is a correct statement about isotopes?

Accepted Answer

Isotopes have the same atomic number $$Z$$ but different mass numbers $$A.$$

Question 6

A radioactive sample has an activity $$R_0 at$$ $$t=0. $$What is its activity after two half-lives?

Accepted Answer

$$R_0/4$

Question 7

Which type of radiation is most penetrating and requires several centimeters of lead to be stopped?

Accepted Answer

Gamma ($$\gamma) $$radiation

Question 8

The energy released in the alpha decay of $$^{238}\mathrm{U} to$$ $$^{234}\mathrm{Th} is $$calculated using the following equation. Which mass values should be used?

Accepted Answer

The mass of $$^{238}\mathrm{U}$$, $$^{234}\mathrm{Th}$$, and $$^4\mathrm{He}$$

Question 9

Which of the following best explains why the mass of a nucleus is less than the sum of the masses of its individual nucleons?

Accepted Answer

Some mass is converted to binding energy according to $$E=mc^2$.

Question 10

A patient receives a 2 mSv dose of gamma radiation. If the absorbed dose is 0.002 Gy and the RBE for gamma rays is 1, what is the dose equivalent in sieverts?

Accepted Answer

$$0.002 Sv$	imes1 = 0.002$ Sv

Question 11

Which of the following is true about the line of stability for nuclei?

Accepted Answer

For light nuclei ($$Z \u003c 16$$), stability is achieved when $$N \approx Z.$$

Question 12

Which of the following best describes the process of beta-minus decay?

Accepted Answer

A neutron turns into a proton and emits an electron.

Question 13

A radioactive isotope is used in medicine and has a half-life of 8 days. If a sample contains $$2.00 	imes 10$$^{12}$$ atoms, how many atoms remain after 24 days?

Accepted Answer

$$2.50 	imes 10$$^{11}$$

Question 14

Which of the following is NOT a property of the strong nuclear force?

Accepted Answer

It acts on electrons and nucleons.

Question 15

Which of the following best describes the principle behind magnetic resonance imaging (MRI)?

Accepted Answer

It measures the absorption of specific frequencies by protons in a magnetic field.

Question 16

Which of the following is the correct equation for the exponential decay of the number of radioactive nuclei $$N at $$time $$t$$?

Accepted Answer

$$N = N_0$ e$$^{-t/	au}$$

Question 17

Which of the following is a real-world application of the concept of half-life?

Accepted Answer

Determining the age of ancient bones using carbon dating.

Question 18

Which of the following statements about the density of nuclear matter is correct?

Accepted Answer

The density of nuclear matter is constant for all nuclei.

Question 19

Which of the following is the correct formula for the binding energy $$B of a $$nucleus in atomic mass units?

Accepted Answer

$$B = (Zm_p + Nm_n - m_{atom}) 	imes 931.49$$ MeV

Chapter 42: Nuclear Physics – Structure, Stability, and Radioactivity

Guida di studio - Domande di pratica

Study guide - Flashcard