It must gain one electron. It must lose one electron. It must gain one proton. It must lose one proton.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A sodium (Na) atom contains 11 protons, 12 neutrons, and 11 electrons. In order to make the sodium ion Na+, what must occur to the sodium atom?
Possibilities:
- It must gain one electron.
- It must lose one electron.
- It must gain one proton.
- It must lose one proton.

It must lose one electron.