Question

why does the na+ ion have a +1 charge? it has gained an extra proton. it has gained an extra electron. it has lost a proton. it has lost an electron.

Explanation:

Atoms are neutral when the number of protons (positive charge) equals the number of electrons (negative charge). Sodium (Na) has 11 protons and 11 electrons in its neutral state. When it forms an ion (\(Na^+\)), it loses one electron. Now, there are 11 protons (total + 11 charge) and 10 electrons (total - 10 charge). The net charge is \(+11-10 = +1\). Gaining a proton would change the element (as the number of protons defines the element). Gaining an electron would make it negatively charged (\(Na^-\)). Losing a proton would also change the element.

Answer:

It has lost an electron.