Question

What is the ionization energy with respect to an element?

Answer 1

`"This is the energy associated........"`

Explanation:

`"This is the energy associated with the formation of 1 mole of"`
`"gaseous cations and 1 mole of gaseous electrons from 1 mole"`
`"gaseous atoms"`.

To put it more simply this is the energy associated with the given reaction.

`M(g) + Delta rarrM^+(g)+e^-`

Thus `Delta="the ionization energy......."`

Both the element, and its cation, are specified to be in the gas phase.

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