Explain why a proton and a H+1 ion are equivalent. Are a Na+1 ion and a proton equivalen; explain your reasoning?

A hydrogen atom (H) contains a proton and an electrons. When hydrogen atom loses an electron, a hydrogen ion (H⁺) is formed which contains a proton only. Hence, a proton and a H⁺ ion are equivalent.

A sodium atom (Na) contains 11 protons, a certain number of neutrons and 11 electrons. When sodium atom loses an electron, a sodium ion is formed which contains 11 protons, a certain number of neutrons and 10 electrons. Obviously, a Na⁺ ion and a proton are NOT equivalent.

Think about how elements are defined.