Question

correct
a neutral al atom has 13 electrons; an al³+ ion is formed when an al atom loses three electrons. therefore,
al³+ has 10 electrons. two of these are located in the 1s orbital, two in the 2s orbital, and six in the 2p orbitals.
the resulting electron configuration is 1s²2s²2p⁶.

part e

what do all the electron configurations have in common?

all of the obtained electron configurations are isoelectronic with group 6a elements.
noble gases.
group 1a elements.
group 7a elements.
group 2a elements.

Explanation:

Isoelectronic species have the same number of electrons. Noble gases have completely filled electron shells. The electron configuration \(1s^{2}2s^{2}2p^{6}\) (for \(Al^{3 +}\) in the example) is the same as that of neon (\(Ne\)), a noble gas. Group 6A, 1A, 7A, and 2A elements do not have this general electron - configuration similarity with the given ion's configuration.

Answer:

noble gases