Physics quiz question: proton-to-neutron process

Physics 205B Quiz 7, Spring Semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Multiple-Choice Question 29.1

Which decay mode turns a proton into a neutron?
(A) α.
(B) β-.
(C) β+.
(D) γ.
(E) (More than one of the above choices.)

Correct answer: (C)

A proton turns into a neutron by emitting a positron and a neutrino:

p -> n + e(+) + neutrino,

which is β+ decay. (This process could also be due to electron capture, which was not discussed in the scope of this course.)

Student responses
Section 31988
(A) : 0 students
(B) : 2 students
(C) : 8 students
(D) : 0 students
(E) : 2 students

Success level: 66%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.40