Final answer:
Atoms gain or lose electrons to achieve noble gas configurations. Sodium forms a cation by losing one electron, phosphorus forms a trianion by gaining three electrons, fluorine forms an anion by gaining one electron, and phosphorous forms a trianion by gaining three electrons.
Step-by-step explanation:
Atoms try to achieve a noble-gas electron configuration, which is eight valence electrons. Sodium loses one electron to achieve the same electron configuration as neon, forming the sodium cation (Na+). Phosphorus gains three electrons to achieve an octet, forming the phosphorus trianion (P3-). Fluorine gains one electron to achieve an octet, forming the fluoride anion (F-). Phosphorous gains three electrons to achieve an octet, forming the phosphorus trianion (P3-).