Assertion: atom's nucleus | /r/MadeOf | proton
Facets:
Source sentences:
text: The neutron had not been discovered when Rutherford proposed his model, which had a nucleus consisting only of protons.
text: When the two proton nuclei of the hydrogen atoms fuse, they form a nucleus consisting of two protons.
text: Atomic nuclei consist of protons and neutrons bound together by the residual strong force.