Question

These diagrams show two atoms of fluorine and an atom of magnesium.

On the left, a purple circle labeled F is shown twice, both times surrounded by 2 concentric circles. The inner circle has 2 small green spheres. The outer circle has 7 small green spheres. On the right, a purple circle labeled M g surrounded by 3 concentric circles. The inner circle has 2 small green spheres. The middle circle has 8 small green spheres. The outer circle has 1 small green sphere.
Which shows the correct steps in the formation of an ionic bond between these atoms?

A magnesium atom accepts six electrons from the fluorine atoms → Each fluorine atom donates three of the electrons → The magnesium atom becomes a -2 ion → Each fluorine atom becomes a +1 ion
A magnesium atom donates two electrons to the fluorine atoms → Each fluorine atom accepts one of the electrons → The magnesium atom becomes a -2 ion → Each fluorine atom becomes a +1 ion
A magnesium atom accepts two electrons from the fluorine atoms → Each fluorine atom donates one of the electrons → The magnesium atom becomes a -2 ion → Each fluorine atom becomes a +1 ion
A magnesium atom donates two electrons to the fluorine atoms → Each fluorine atom accepts one of the electrons → The magnesium atom becomes a +2 ion → Each fluorine atom becomes a -1 ion

Answer 1

The last option is correct:

A magnesium atom donates two electrons to the fluorine atoms → Each fluorine atom accepts one of the electrons → The magnesium atom becomes a +2 ion → Each fluorine atom becomes a -1 ion.

Reason: Mg (2,8,2) loses its two valence electrons to achieve an octet (becomes Mg2+). Each F (2,7) gains one electron to complete its octet (becomes F−). The oppositely charged ions attract to form the ionic compound MgF2.