Assertion: plutonium's property | /r/HasProperty | studied
Facets:
value: during this time
type: TEMPORAL
Source sentences:
text: The nuclear properties of plutonium-239 were also studied; researchers found that when it is hit by a neutron it breaks apart (fissions) by releasing more neutrons and energy.
text: The nuclear properties of plutonium-239 were also being studied and researchers found that when hit with a neutron it fissions by releasing energy and more neutrons.
text: During this time, the nuclear properties of plutonium-239 were also studied.