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Define Ionization Energy.
The amount of energy required to remove one mole of electrons from one mole of atoms or ions in the gaseous state to produce one mole of positive ions, is called ionization energy / ionization potential of the concerned element.
Symbol: IE
Unit: kJ/mol [Read: Kilojoules per mole]
Expression:
Read our post on defining Electron Affinity properly and completely.
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