Can someoneme which of these cannot be a product of a fission reaction? a. neutron b. a new element c. a less massive atom d. a more massive atom a radioactive isotope is a type of that will change into another isotope. a. molecule b. neutron c. proton d. atom often in fission reactions, a single can act like a billiard or pool ball by cracking apart atomic nuclei. select one: a. element b. neutron c. nucleus d. atom