That would make a cation. If it gained one instead, then it would make an anion.
D. The atomic mass in amu is basically the number or nuclei since the mass of the electrons is negligible. For a given atom (element) the number of protons is fixed. Say the element has 10 protons. If the atomic weight is 14 atomic mass units (amu), you know that there are 4 neutrons, since both neutrons and protons are 1 amu each and there are 10 protons
When a relationship between two different things is shown in a fraction it is a ratio.
hope this helps :)
Unlike charges attracting each other