The charge on an individual atom is represented using a superscript placed to the upper right of the atomic symbol. Here's how it works:

* Positive charge: A plus sign (+) followed by a number indicates the number of positive charges. For example, Na+ represents a sodium atom with a +1 charge.

* Negative charge: A minus sign (-) followed by a number indicates the number of negative charges. For example, O2- represents an oxygen atom with a -2 charge.

* Neutral charge: No superscript is used to indicate a neutral atom, which has an equal number of protons and electrons.

Examples:

* H+ - Hydrogen ion with a +1 charge

* Cl- - Chloride ion with a -1 charge

* Ca2+ - Calcium ion with a +2 charge

* N3- - Nitride ion with a -3 charge

* Fe - Iron atom (neutral)

Important Note: The charge on an atom represents the difference between the number of protons (positive charge) and electrons (negative charge).