Which atoms form ionic bond?

a. two sodium atoms

b. two fluorine atoms

c. magnesium and lithium

d. magesium and bromine?

Ionic bonds form always form between a metal and a nonmetal, so the answer is D, Magnesium and Bromine.

Sodium is a metal, so a bond between two Sodium atoms will not be ionic.

Fluorine is a non-metal, so a bond between two will be covalent bond instead of an Ionic.

Magnesium and Lithium are both metals, so a bond will not be ionic.

On the other hand, Magnesium is a metal and Bromine is a non-metal, so a bond between them will be ionic.