How can I calculate the net charge of an ion?
There 2 important things you need to understand here: protons and electrons. All elements are neutral because they have a balance of electrons and protons.
If you remove an electron (you are removing a negative charge) there will be more protons to electrons. This means there will be an overall positive charge. Seeing as there is only a single electron removed- you will have +1 net charge.
If you add an electron = excess of electrons=overall negative charge
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