Answer: It becomes an Ion
When an atom has gained or lost electrons (negative charge), it becomes an ion.
In this sense:
Ions are atoms that have gained or lost electrons in their electronic cortex.
If a neutral atom loses electrons, it remains with an excess of positive charge and transforms into a positive ion or cation, whereas if a neutral atom gains electrons, it acquires an excess of negative charge and transforms into a negative ion or anion.
It is then how ions form bonds with other atoms differently depending on the number of electrons they have.