12) Which of the following types of nuclear changes happens
spontaneously in nature on earth?
A. fusion
B. fission
C. radioactive decay
13) Which of the following types of nuclear changes is a form of induced transmutation?
A. alpha decay
B. fission
C. beta decay
D. gamma decay
14) Uranium-235 fission is induced by which particle striking the uranium nucleus?
A. alpha
B. beta
C. fast neutron
D. slow neutron