Assertion: atom's neutron | /r/HasProperty | 7 – 3 = 4
Facets:
Source sentences:
text: For example, a lithium atom (Z=3, A=7 amu) contains three protons (found from Z), three electrons (as the number of protons is equal to the number of electrons in an atom), and four neutrons (7 – 3 = 4).