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An ion is an atom or group of atoms that have a net electrical charge. An ion is formed when electrons or protons are gained or lost by an atom. This is different than a neutral atom that has equal numbers of protons and electrons so there is no net electrical charge.

A simple ion is made up of only one charged atom with either a positive or negative charge. A complex ion is one with a number of atoms with a net charge that is positive or negative. If an atom or atoms lose electrons or gain protons, the ion has a positive charge. This kind of ion is called a cation. If an atom or atoms gain electrons or lose protons, the ion will have a negative charge. This kind of ion is called an anion. Ions normally are found as neutral groups of cations and anions combined. This means when the cations and anions charges are added up, the total is zero.

How are ions created from neutral atoms? Some such as salt compounds come apart or dissociate in certain solutions. Substances that form ions in solutions are called electrolytes. Those that don't form ions in solutions are called non-electrolytes. Electrolytes conduct electricity.

Ions can also be formed from neutral atoms with radiation. They can also be formed by having a substance heated to high temperatures.


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