Answer the following question given this paragraph: 

By losing an electron, the sodium atom becomes a sodium ion. It now has one less electron than protons, giving it a charge of +1. Positive ions such as sodium are given the same name as the element. The chemical symbol has a plus sign to distinguish the ion from an atom of the element. The symbol for a sodium ion is Na + .


Q: What happens when a sodium atom loses an electron?

 Choices:

- becomes calcium

- gains a proton

- combines with hydrogen

- becomes sodium ion

A:
becomes sodium ion
