Question

1.a radioscope which is neutron poor and very heavy is most likely to decay by?

alpha , beta, electron capture, positron emission

2. When a 235-U nucleus is struck by a thermal neutron, fission occurs often with the release of neutrons. If fission fragments are 89-Sr and 144-Xe, how many neutrons are released?

Alpha emission, electron capture, and positon emission are possible for neutron poor radioisotopes. The most likely is alpha.

For part 2, first calculate the number of neutrons in 89Sr and 144Xe. How do you do that?
Look up the atomic number for Sr. That is 38. The number of neutrons, then, is 89-38=??

Do the same thing for Xe. Add the neutrons together.
Now determine the number of nuetrons in 235U which is 235-92. The difference between what was available in U and what was obtained (Sr+Xe) is the number of neutrons that were released. Post your work if you get stuck.

Answer 1

1) alpha emission