Assertion: polonium's number | /r/HasProperty | needed as result
Facets:
value: to form a stable nucleus
type: PURPOSE
Source sentences:
text: As a result, as the number of protons increases, an increasing ratio of neutrons to protons is needed to form a stable nucleus.
text: As a result, as the number of protons increases, an increasing ratio of neutrons to protons is needed to form a stable nucleus.