Chlorine has seven valence electrons. It can form a bond with two atoms of Magnesium (two valence electrons). Is this an example of an ionic or covalent bond? Explain your reasoning by comparing both types of bonds. Is each atom gaining, losing, or sharing electrons?

The answer to your question is Ionic bonding. Magnesium loses 2 electrons and Chlorine gains 1 electron

Explanation:

An Ionic bond is formed between a metal and a nonmetal and the difference of electronegativity is higher than 1.7. In this type of bond, metals lose electrons and nonmetals gain them.

Covalent bonding is formed between two nonmetals and the difference of electronegativity is between 0 and 1.7. Elements share electrons.

Process

Electronegativity of Mg = 1.31

Electronegativity of Cl = 3.16

Difference = 3.16 - 1.31

                  = 1.85

          1.85 > 1.7 then the bond formed is Ionic

Magnesium loses 2 electrons and Chlorine gains 1 electron

the first point, i am pretty sure.