# What is successive ionization energy?

Feb 4, 2017

Well, it is the energy required to produce ${M}^{2 +}$ from ${M}^{+}$ or ${M}^{3 +}$ from ${M}^{2 +} \ldots \ldots \ldots . .$

#### Explanation:

By definition, the first ionization energy is the energy required to produce one mole of gaseous cations, and one mole of electrons, from one mole of gaseous atoms:

$M \left(g\right) + {\Delta}_{1} \rightarrow {M}^{+} \left(g\right) + {e}^{-}$

As is typical, $\Delta$ increases across a Period, from left to right as we face the Table, and decreases down a Group. The increase is due to the increased nuclear charge; the decrease is due to the separation of the valence electron from the nuclear charge.

The second ionization energy, ${\Delta}_{2}$, relates to the formation of dications from the given cation:

${M}^{+} \left(g\right) + {\Delta}_{2} \rightarrow {M}^{2 +} \left(g\right) + {e}^{-}$

${\Delta}_{2}$ should be intrinsically greater than ${\Delta}_{1}$ inasmuch as it should require more energy to abstract an electron from a positively charged particle than from a neutral one.

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