Why can't sodium gain positive charge by aquiring a proton in it nucleus?

Answer 1

Elements are defined by the number of protons they have (their atomic number). If sodium "gained" a proton, it would become a magnesium atom. However, atoms cannot just "gain" and "lose" protons like it can electrons. Through nuclear decay processes, however, protons and neutrons can "interconvert." For example, a neutron can "turn into" a proton via beta decay.

Answer 2

Sodium cannot gain a positive charge by acquiring a proton in its nucleus because sodium has a fixed number of protons in its nucleus, which determines its identity as an element. Adding another proton would change the element to a different one.