Atomic Theory: Structure of the Atom: Students use the terms isotope, atomic number, mass number, and atomic mass to determine the number of subatomic particles in an isotope of an element.

Ever since the nucleus of the atom was discovered in 1911, scientists have split, fused and smashed nuclei together to unravel its internal structure. Among the numerous researchers worldwide who are ...

The Bohr model is a neat but quite imperfect depiction of the inner workings of an atom before things got too muddled up by quantum principles.