Answer to Question #263275 in General Chemistry for abby

Question

• Choose an alkali metal, an alkaline earth metal, a noble gas, and a halogen so that they constitute an isoelectronic series when the metals and halogen are written as their most stable ions.

Answer 1

An isoelectronic series is a group of atoms/ions that have the same number of electrons

Alkali metals are Group I elements in periodic table. Example Na, its stable ion is Na⁺

Alkaline earth metals are Group II elements in periodic table. Example Mg , its stable ion is Mg²⁺

Halogen are Group VII elements in periodic table. Example Fluorine, its stable ion is F^-

Noble gases are Group VIII elements in periodic table

They have full outermost energy levels and their atoms are stable. Example Ne

Na⁺ ,Mg²⁺ ,F^- and Ne, have equal number of electrons with electronic configuration 1s² 2s² 2p⁶

$\therefore$ They belong to isoelectronic series