[Hemsida]

Radiochemistry and Nuclear Chemistry self-test # 4

Comprises Chapter 4

This is a self grading test of your knowledge. It consists of 20 randomly chosen questions with single or multiple answers. The questions with single answers have round buttons and the questions with perhaps more than one correct answer have square buttons. Answer the questions by clicking on the corresponding button in the list of alternative answers. On questions with a single answer (round buttons to click on), it is only possible to mark one of the alternative answers as correct.
Grading of the completed test is automatic when you click on the button marked "GRADE MY ANSWERS" at the end of the test.
Correct answers can be read by clicking on the button having the same number as the question. You find these buttons at the end of the test. You can also refresh your memory first by jumping directly to the answer buttons and click on them to get answers and read relevant parts of the book before doing this test.
On the questions with one or more possible answers (squares to click on) only the first click on each button is recorded as an answer. Hence you must click on the reset button below the question before you can change the original answer(s). Failure to do this will probably make the answers on this question regarded as wrong in the grading process.
Please observe that your teacher may require a deeper understanding of the treated subject than reflected by this test. In case you have any valuable comments or questions regarding this self-test, explain them in an e-mail to: jol@nc.chalmers.se 


Question # 1 (One or more answers) By successive decay is meant a decay that

    A) occurs in a haphazard way
    B) occurs in a series of mother-daughter nuclides
    C) has     g-emission before each a-decay
    D) emits more than one     g-ray in series
    E) gives rise to more than one type of nucleus in each decay

In case of an error in the answers above, please click on this button before making any corrections 

Question # 2 (One or more answers) Which of the following are laws valid for radioactive decay?

    A) The conservation of mass number
    B) The conservation of neutron number
    C) The conservation of total energy
    D) The conservation of linear momentum
    E) The conservation of total charge

In case of an error in the answers above, please click on this button before making any corrections 

Question # 3 (One answer) The rate and energy in radioactive decay is affected

    A) by the pressure
    B) by the temperature
    C) by the chemical oxidation state
    D) by gravity
    E) by none of those mentioned above

Question # 4 (One or more answers) Radioactive equilibrium means that

    A) all chemical reactions have ended
    B) decay rates are the same in a mother-daughter pair
    C) radioactive decay is so rapid that the chemical equilibrium is not disturbed
    D) all decaying nuclei have reached their final energy
    E) formation of a nuclide occurs with the same rate as its decay

In case of an error in the answers above, please click on this button before making any corrections 

Question # 5 (One or more answers) In which of the following types of radioactive decay are elementary particles emitted which all have discrete energies?

    A) Alpha decay
    B) Beta- decay
    C) Electron capture
    D) Beta+ decay
    E) Gamma emission

In case of an error in the answers above, please click on this button before making any corrections 

Question # 6 (One or more answers) In which of the following decay types are the masses of two electrons always present in the formula for calculation of the Q-value from reactant and product masses?

    A) Alpha decay
    B) Beta- decay
    C) Electron capture
    D) Beta+ decay
    E) Spontaneous fission

In case of an error in the answers above, please click on this button before making any corrections 

Question # 7 (One or more answers) The decay energy in b-decay is quatized. Hence, it is true that

    A) all emitted b-particles have the same energy
    B) a     b-sönderfall can't be followed by -decay can't be followed by -decay can't be followed by -decay can't be followed by g-emission
    C)     b-decay is always preceded by g-emission
    D)     b-particles have a broad energy distribution
    E) neutrinos are always emitted in     b-decays

In case of an error in the answers above, please click on this button before making any corrections 

Question # 8 (Yes/No) Is it true that a recoiling daughter nuclide always moves in the same direction as the emitted radiation?

    A) Yes
    B) No

Question # 9 (One answer) The Q-value for a-decay can be calculated by using one of the following equations. Which one?

    A) Q = ½ m v2
    B) Q = (m - mo) c2
    C) Q = p2/(2m)
    D) Q = -931.5 (MZ-2 + MHe - MZ)
    E) Q = 2 e2 B2 r2/mHe

Question # 10 (One or more answers) By a branching decay means a decay that

    A) leads to different products
    B) has a half-life that changes slowly with time
    C) has partial half-lives
    D) always gives rise to a series of mother-daughter pairs
    E) has a jumping half-life

In case of an error in the answers above, please click on this button before making any corrections 

Question # 11 (One answer) Elements with atomic numbers above 92 do not occur naturally on Earth because

    A) they were not formed during element synthesis in "our" supernova explosion
    B) they have too short half-lives compared to the age of Earth
    C) their large density have forced them to migrate into the center of Earth
    D) their occurrence on Earth has not yet been proven
    E) they have all fissioned by being fuel for natural nuclear reactors similar to Oklo

Question # 12 (One or more answers) By the half-life of a radionuclide is meant

    A) the time needed for a given number of atoms to decrease to half that number
    B) the number of atoms that may decay within that time
    C) the time needed to decrease the Q-value to half its initial value
    D) the slope of a straight line in a diagram with radioactivity plotted against time using linear scales
    E) the time needed for the atoms to initiate their decay

In case of an error in the answers above, please click on this button before making any corrections 

Question # 13 (One answer) The unit for radioactivity in the SI-system is

    A) Bq/s
    B) Ci
    C) cps
    D) Bq
    E) Hz

Question # 14 (One or more answers) The radioactive decay of a nuclide is always characterized by

    A) a constant half-life (although a few exceptions are known)
    B) a slowly decreasing decay constant
    C) a quantized energy release
    D) a whole-numbered change in the nuclear spin quantum number
    E) the emission of a neutron with the speed of light

In case of an error in the answers above, please click on this button before making any corrections 

Question # 15 (One or more answers) By mixed decay one means a radioactive decay where

    A) more than one kind of radiation is emitted simultaneously
    B) the decays stems from more than one radionuclide
    C) the decay of the nuclide gives rise to several different products
    D) the     b-decay is always preceded by a g-ray emission
    E)     a-decay competes with spontaneous fission

In case of an error in the answers above, please click on this button before making any corrections 

Question # 16 (One or more answers) For which of the following decay modes is both the speed of light and the mass of the daughter nuclide used in the equation for calculating the recoil energy?

    A) Alpha decay
    B) Beta- decay
    C) Beta+ decay
    D) Electron capture
    E) Gamma emission

In case of an error in the answers above, please click on this button before making any corrections 

Question # 17 (One answer) The mass of a particle moving at high velocity can be calculated by

    A) m = mo/(1-(v/c)2)½
    B) m = moc2
    C) m = p2/(2mo)
    D) m = -931.5 (MA - MZ) v2
    E) m = Ekin2mo

Question # 18 (One or more answers) A radioisotope generator is a device used in order to

    A) produce electric power in some space crafts
    B) produce new types of radionuclides
    C) produce a short lived radionuclide from a long lived mother
    D) produce energy in a nuclear power station
    E) measure neutrinos

In case of an error in the answers above, please click on this button before making any corrections 

Question # 19 (One or more answers) Heisenberg's uncertainty principle

    A) predicts a radioactive decay of stable nuclei
    B) yields the minimum value of conjugated variables
    C) is only valid as long as the universe expands in all directions
    D) permits an estimate of half-lives from line widths
    E) requires that electrons are near atomic nuclei

In case of an error in the answers above, please click on this button before making any corrections 

Question # 20 (One answer) Which of the following decay modes give the largest daughter recoil energy at a given Q-value?

    A) Alpha decay
    B) Beta decay
    C) Electron capture
    D) Gamma emission
    E) Neutron emission

Correct answers to each question can be obtained by clicking on the corresponding button below

[Back to our homepage]
(Updated 2001-08-19)