Final answer:
The Lewis structure for CaF₂ shows Ca²⁺ with no dots representing the lost valence electrons, and two F⁻ ions each with eight dots showing the gained electron to complete the octet.
Step-by-step explanation:
To draw the Lewis structure for the compound CaF, you need to consider the elements involved, calcium (Ca) and fluorine (F). Calcium has two valence electrons which it can readily donate, and fluorine has seven valence electrons and wishes to gain one more to complete its octet.
First, write the symbol for calcium and fluorine, then place dots around the symbols representing their valence electrons. Calcium will lose its two electrons to become a Ca²⁺ ion, as depicted by its symbol with no dots. Each fluorine atom will gain one electron to complete its octet, forming an F⁻ ion, represented by a symbol surrounded by eight dots. Since calcium donates two electrons, it typically bonds with two fluorine atoms to form the ionic compound CaF₂.
The Lewis structure for CaF₂ can be visualized as Ca²⁺ with no dots since it has lost its valence electrons, paired with two brackets each enclosing a fluorine symbol surrounded by eight dots ([F⁻]) with a negative sign to indicate each gained electron.