Show with dot and cross diagram of the formation of ions in the reaction of Fluorine with sodium ions.

Electron dot diagram is attached below

Explanation:

Sodium is alkali metal and present in group one. It has one valence electron. All alkali metal form salt when react with halogens.

Sodium loses its one electron to get stable.  While all halogens have seven valence electrons they need only one electron to get stable electronic configuration.

When alkali metals such as sodium react with halogen fluorine it loses its one valence electron which is accepted by fluorine and ionic bond is formed. The compound formed is called sodium fluoride.

Na + F   →   NaF

In cross and dot diagram electrons of one atom are shown as dots while other atom shown as cross to distinguish.

Electron dot diagram is attached below.

the atomic mass is the bottom number on the element.

-steel jelly

i'm pretty sure its b i might be wrong though!