Final answer:
Four species that are isoelectronic with the magnesium ion, mg2+, include neon, fluoride ion, sodium ion, and aluminum ion.
Step-by-step explanation:
When determining species that are isoelectronic with the magnesium ion, Mg2+, we need to consider ions and neutral atoms with the same number of electrons. Since the magnesium ion, with a charge of 2+, has lost 2 electrons, we need to look for species that also have 10 electrons. Here are four examples:
- Neon (Ne) is a neutral atom and has 10 electrons.
- Fluoride ion (F-) has gained 1 electron, and the resulting charge is -1. It has 10 electrons as well.
- Sodium ion (Na+) has lost 1 electron, and the resulting charge is +1. It also has 10 electrons.
- Aluminum ion (Al3+) has lost 3 electrons, and the resulting charge is +3. Like the other examples, it has 10 electrons.
These four species are isoelectronic with the magnesium ion because they all have the same number of electrons, which is 10.