Question

Which of the following atoms and ions is (are) isoelectronic with S^2+ ? Show answer choices As^3+ Cl^3+ Si^4+ Ar

Answer 1

Atoms and ions that have the same electron configuration are said to be isoelectronic. The number of protons determines the size of isoelectronic species, with a greater nuclear charge corresponding to a smaller radius.

Step-by-step explanation:

Atoms and ions that have the same electron configuration are said to be isoelectronic. Examples of isoelectronic species are N³, 0²-, F¯, Ne, Na+, Mg2+, and Al³+ (1s²2s²2p6). Another isoelectronic series is P³-, S²-, Cl-, Ar, K+, Ca²+, and Sc³+ ([Ne]3s²3p6). For atoms or ions that are isoelectronic, the number of protons determines the size. The greater the nuclear charge, the smaller the radius in a series of isoelectronic ions and atoms.

Answer 2

Ar (Argon) is the atom that is isoelectronic with S²+ since it has the same number of electrons (18) as S²+.

Step-by-step explanation:

The atoms and ions that are isoelectronic with S²+ have the same electron configuration as S²+, which has 16 electrons (the sulfur atom normally has 16 protons and 16 electrons, but S²+ has lost 2 electrons). We can determine the isoelectronic species by looking at the atomic number and subtracting the charge to find the number of electrons.

• Si⁴+ (atomic number 14, 14 - 4 charge = 10 electrons, not isoelectronic)
• Cl³+ (atomic number 17, 17 - 3 charge = 14 electrons, not isoelectronic)
• Ar (atomic number 18, neutral charge = 18 electrons, isoelectronic)
• As³+ (atomic number 33, 33 - 3 charge = 30 electrons, not isoelectronic)

Therefore, Ar (Argon) is the atom that is isoelectronic with S²+.