2
$\begingroup$

It was stated in a textbook that the first ionisation energy is

the minimum energy needed to remove one mole of electrons from one mole of gaseous atoms in their ground state

Is there a difference between ionisation energy and first ionisation energy?

$\endgroup$

closed as unclear what you're asking by Mithoron, Tyberius, M.A.R., andselisk, Todd Minehardt Sep 13 '17 at 16:18

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • $\begingroup$ There is a first, second, third, fourth, … ionisation energy. Does that answer your question? $\endgroup$ – Jan Sep 13 '17 at 11:05
  • $\begingroup$ @Jan not really. chemguide.co.uk/atoms/properties/moreies.html explains the successive ionisation energies with the equations, but ionisation energy isn't explained. $\endgroup$ – George Tian Sep 13 '17 at 11:17
  • 3
    $\begingroup$ Well, ionisation energy is the general term and first ionisation energy specifies. As you would expect from language. $\endgroup$ – Jan Sep 13 '17 at 11:24
  • 1
    $\begingroup$ en.wikipedia.org/wiki/Ionization_energy $\endgroup$ – Mithoron Sep 13 '17 at 14:09
3
$\begingroup$

There is no difference between "ionization energy" and "first ionization energy". Another definition from Wikipedia:

The ionization energy (IE) is qualitatively defined as the amount of energy required to remove the most loosely bound electron, the valence electron, of an isolated gaseous atom to form a cation.

Here it's more clear that they are the same, since "the most loosely bound electron" is a single electron, and each successive ionization only removes a single electron at a time.

Additionally, if one were to remove all electrons from an atom, it would be explicitly stated as "complete ionization".

$\endgroup$
  • $\begingroup$ From both your and my definitions, I can see a difference. Can I confirm that the difference is that ionisation energy removes electrons from ONE atom, while the first, second third... ionisation energy removes electrons from ONE MOLE of atoms? $\endgroup$ – George Tian Sep 14 '17 at 11:14
  • $\begingroup$ No. The definition of ionization energy is $\ce{X + \text{energy} -> X+ + e-}$, with nothing about atoms or moles. It's all about the units, which work out to be per mole. Units are consistent between all successive ionization energies. $\endgroup$ – pentavalentcarbon Sep 14 '17 at 12:27

Not the answer you're looking for? Browse other questions tagged or ask your own question.