What are the formula of ions formed by the following elements? Hydrogen, Helium, Lithium, Beryllium, Boron, Nitrogen, Oxygen, Fluorine.

The ions (whether cations or anions) formed by an element, depend upon the number of electrons that need to be lost or gained, in order to achieve a fully filled orbital. When electrons are lost, cations are formed. When electrons are gained, elements form anions.

For example, hydrogen has only 1 electron and it loses it to form a cation `H^+` . In comparison, helium has 2 electrons and fully filled electronic orbital and hence does not require any electron gain or lose. Thus, helium is a noble gas and does not form an ion. Similar to hydrogen, lithium loses one electron and becomes `Li^+` . In comparison, beryllium is form `Be^(2+)` . Boron forms `B^(3+)` , nitrogen forms `N^(3-)` , oxygen form `O^(2-)` and fluorine form `F^-` . 

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