1. Fission fragments are typically
(a) B+ emitters.
(b) B- emitters.
(c) Both.
(d) Neither.
2. Which of the following properties would decrease the critical mass needed to sustain a nuclear chain reaction?
(a) Low boiling point.
(b) High melting point.
(c) More neutrons released per fission.
(d) Low nuclear density.
(e) Filled valence shell.
(f) All of the above.