+2 charge on an ion means the given ion has 2 extra electrons.
In chemistry,
We often use symbols like plus (+) and minus (-) which is usually written in the superscript of the ions.
As + is given when the given ions have extra electrons.
As we know,
Every atom/ ion needs to complete an octet in its outermost orbit for becoming stable.
So, if in any of the ion +2 is written it means that the given ions have 2 extra electrons present in their outermost orbit and once the ion release those 2 extra electrons it becomes cationic in nature.
Similarly, if -2 is written it means that the given ions have 2 deficit electrons in their outermost orbit, so for becoming cationic the ions need 2 electrons.
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