Question

How do positive and negative ions form?

Answer 1

See below.

Explanation:

They form through Ionic bonding.

Elements gain or lose electrons to form ions and to gain full outer shells.

For example, let's look at Lithium and Fluorine:

Lithium has `3` electrons, so it needs to lose one to gain a full outer shell.

Fluorine would gain this electron to have `10` electrons, giving it `2` full outer shells.

The Lithium atom would turn into an `Li^+` ion with an electronic configuration of `2`, as an electron has a negative charge, losing one would give a positive charge.

The Fluorine atom would change to a `F^-` ion with an electronic configuration of `2,8` as it gains a negatively charged subatomic particle, so it turns negative as the atom of an element always has a charge of `0`.

This would form lithium fluoride as a result of this ionic bonding.