An atom can become an ion by losing electrons. It can accomplish the same thing by gaining electrons.
An atom becomes a positively charged ion when it loses one or more electrons.
Ion
An atom can become an ion by either gaining or losing electrons. If it gains electrons, it becomes an anion. If it loses electrons, it becomes a cation. An ion is merely an atom with a charge, either positive or negative.
Oxide is the ion form of oxygen. It forms when an oxygen atom gains an extra two electrons. So an oxide ion would become an oxygen atom by losing two electrons.
A sodium atom becomes a sodium ion, when a neutron is added to the nucleus.
electrons
If the atom was not a negative ion prior to losing an electron, it becomes a positive ion.
Since electrons are negatively charged, losing an electron will make the hydrogen atom become a positively charged ion.
This is by gaining (-) or losing (+) electrons
It would become an Aluminum ion that has a 3+ charge
By losing one or more electrons
Helium is a neutral atom that has several isotopes and can become an ion.