Final answer:
The ranking from highest to lowest ionization energy for Ne, Mg2+, Mg, and O2- is Neon (Ne), Magnesium ion (Mg2+), Magnesium (Mg), and Oxide ion (O2-) respectively. This order reflects the stability of neon's electron configuration and the effects of the effective nuclear charge on the species.
Step-by-step explanation:
To rank the peak with the highest ionization energy from highest to lowest for the species Mg2+, Mg, Ne, O2-, we must consider the effective nuclear charge and electron configurations.
- Neon (Ne) will have the highest ionization energy because it is a noble gas with a stable electron configuration.
- Magnesium ion (Mg2+) will have the next highest ionization energy as it has lost two electrons, resulting in a higher effective nuclear charge compared to neutral magnesium (Mg).
- Magnesium (Mg) will follow because it still has a relatively high effective nuclear charge and is closer to achieving a noble gas configuration than the oxide ion.
- Oxide ion (O2-) will have the lowest ionization energy because it has gained two electrons, resulting in reduced effective nuclear charge and a larger electron cloud, which makes it easier to remove an electron.
Thus, the order from highest to lowest ionization energy is: Ne > Mg2+ > Mg > O2-.