No, a sodium ion (Na+) does not have 8 valence electrons. Sodium is an alkali metal located in Group 1 of the periodic table. It has an atomic number of 11, which means it has 11 electrons in its neutral state.
In its neutral state, sodium has one valence electron in its outermost energy level (specifically, the 3s orbital). However, when sodium forms an ion by losing this valence electron, it achieves a stable electron configuration similar to that of a noble gas. In the case of sodium, it loses its single valence electron to form a +1 ion, resulting in a stable configuration with 8 electrons in its outermost energy level, which is now the second energy level.
So, the sodium ion (Na+) has a total of 10 electrons, with the electron configuration of 1s² 2s² 2p⁶. This configuration satisfies the octet rule, with 8 valence electrons in the outermost energy level.