Answer:
An ion is an atom or group of atoms that has an electric charge. When an atom loses an electron, it loses a negative charge and becomes a positive ion. When an atom gains an electron, it gains a negative charge and becomes a negative ion. a sodium ion forms when a sodium atom loses one electron and becomes positively charged. a chloride ion forms when a chlorine atom gains one electron and becomes negatively charged.
Hope this helps,
Arabella