Assertion: atom's neutron | /r/HasProperty | released by fission
Facets:
Source sentences:
text: A small amount of uranium-235, say 0.45 kg (1 pound), cannot undergo a chain reaction and is thus termed a subcritical mass; this is because, on average, the neutrons released by a fission are likely to leave the assembly without striking another nucleus and causing it to fission.
text: This means you need enough U-235 or Pu-239 to ensure that neutrons released by fission will strike another nucleus, thus producing a chain reaction.