A stable sodium ion will have a charge of +1.
Explanation: Sodium (Na) is an alkali metal found in Group 1 of the periodic table. In its stable form, sodium has lost one electron, which gives it a positive charge. An atom of sodium has 11 protons and 11 electrons in its neutral state. When it loses one electron, it is left with 11 protons and only 10 electrons, resulting in an overall positive charge of +1. This makes the sodium ion (Na+) stable as it achieves a full outer electron shell, resembling the electron configuration of the nearest noble gas, neon.