The isotope 3475 Se is used medically for the diagnosis of pancreatic disorders.
How many protons, electrons, and neutrons does an atom of 3475 Se have?
The symbol of an element contains its mass number or atomic mass and its atomic number.
Recall that the mass number or atomic mass of an element represents the total number of its protons and neutrons, while the atomic number represents the total number of its protons. For an element that is neutral, the atomic number also represents the total number of its electrons.