8. When sodium and fluorine combine to produce the compound NaF, the ions formed have the same electron configuration as atoms of (1) argon, only (2) neon, only (3) both argon and neon (4) neither argon nor neon

When sodium (Na) and fluorine (F) combine to form sodium fluoride ( ), sodium loses one electron to become and fluorine gains one electron to become . The resulting and ions have electron configurations that match the nearest noble gas. Sodium has the atomic number 11 and when it loses one electron, it has the configuration of neon ( , with 10 electrons). Fluorine has the atomic number 9 and gains one electron to also have the electron configuration of neon ( , with 10 electrons). Therefore, the ions formed in have the same electron configuration as neon.