Weegy: The answer is C. 2, 1. User: In the following nuclide, which number is the mass number?
D. none of these Weegy: C. 2,1
In the modern Standard Model of particle physics, the proton is a hadron, composed of quarks. Prior to that model becoming a consensus in the physics community, the proton was considered a fundamental particle. [ In the modern view, a proton is composed of three valence quarks: two up quarks ... (More)