Question

when placed in a cloud chamber, a radioactive substance does which of the following?
select one:
a. leaves a trail of condensed water vapor.
b. produces an electric current.
c. ionizes chemicals on the film present in the chamber
d. causes a liquid to reach its boiling point.

the splitting of a nucleus into two smaller nuclei of roughly equal mass is called...

select one:
a. alpha decay.
b. nuclear fission.
c. beta decay.
d. nuclear fusion.

Explanation:

For the first question: A cloud chamber works by making ionized particles from radiation act as condensation nuclei, forming visible trails of condensed water vapor. Options b, c, and d describe functions of other radiation detectors (like Geiger counters, film badges, and bubble chambers respectively).
For the second question: Nuclear fission is defined as the splitting of a large atomic nucleus into two smaller, roughly equal mass nuclei. Alpha and beta decay are forms of radioactive decay that emit particles without splitting the nucleus into two large fragments, while nuclear fusion is the combining of small nuclei into a larger one.

Answer:

1. a. Leaves a trail of condensed water vapor.
2. b. nuclear fission.