Question

question 3 (2 points)
the calcium cation and chloride anion are ____________________ because they both have the same electron configuration.

the same size
isoelectronic
the same charge
like neon

Explanation:

Isoelectronic species are those that have the same number of electrons. A calcium cation (\(Ca^{2+}\)) has lost 2 electrons. Calcium has an atomic number of 20, so \(Ca^{2+}\) has \(20 - 2=18\) electrons. A chloride anion (\(Cl^{-}\)) has gained 1 electron. Chlorine has an atomic number of 17, so \(Cl^{-}\) has \(17 + 1 = 18\) electrons. They have the same electron configuration. Size is not the same as ionic radius depends on nuclear charge (more protons in \(Ca^{2+}\) pull electrons closer). Charges are different (\(+2\) for \(Ca^{2+}\) and \(-1\) for \(Cl^{-}\)). Neon has 10 electrons, while \(Ca^{2+}\) and \(Cl^{-}\) have 18 electrons.

Answer:

isoelectronic