CH301 Fall 2009 Practice Quiz 2 Answer Key 1. What is the ground state electron configuration for silver (Ag) ?a. [Kr]4d105s1b. [Kr]5s24d9c. [Kr]5s25d9d. [Kr]3d94s1Certain members of the d-transition metals can "borrow" nearby s electrons in order to half-fill or fill their d subshell.2. Calculate the effective nuclear charge experienced by the valence electrons in a neutralgermanium (Ge) atom.a. 14b. 4c. 2d. 10Valence electrons are those contained within the outermost energy level. To calculateeffective nuclear charge the number of shielding electrons (all electrons in lower energylevels) are subtracted from the actual nuclear charge (number of protons in the nucleus).32 - 28 = 43. Arrange the following atoms in order of increasing electron affinity: Na, N, Cl, Cua. Cu < Cl < Na < Nb. Na < Cu < N < Clc. Cl < Cu < Na < Nd. N < Na < Cu < ClIn general, electron affinity follows the same trend as ENC. Nitrogen however has the lowestaffinity because it has a half filled p subshell, which results in extra stability. Therefore it willnot want to add an electron to its subshell. Although electron affinity typically decreasesdown the periodic table copper will have a higher electron affinity than sodium because itonly needs 1 electron to complete its d subshell.4. Arrange the following in order of decreasing ionic radius: Cu+, Ga3+, Ge4+, Zn2+.a. Cu+> Zn2+> Ge4+> Ga3+b. Cu+> Zn2+> Ga3+> Ge4+c. Zn2+> Cu+> Ga3+> Ge4+d. Ge4+> Ga3+> Zn2+> Cu+The set of isoelectronic ions (Cu+, Zn2+, Ga3+, Ge4+) have the same number of electrons,but germanium has the greatest number of protons with which to attract them and copperhas the least, with zinc and gallium having incrementally more as they appear on theperiodic table.5. What is the electronic configuration of gold (Au)?a. [Xe] 6s15d10b. [Xe] 6s24f145d9c. [Xe] 6s24f135d10d. [Xe] 6s14f145d10Gold is a member of the d block which is able to"borrow" nearby s electrons in order to half-fill its d subshell.6. Which atom, oxygen or nitrogen, has the higher ionization energy?a. Nitrogen, because it has a lower effective nuclear chargeb. Nitrogen, because it has a stable, half-filled p subshell and removing an electrondecreases its stabilityc. Oxygen, because it has a higher effective nuclear charged. Oxygen, because it does not have a stable, half-filled p subshell and removing anelectron increases its stabilityIn general, a filled or half-filled subshell will afford an atom or ion additional stabilityrelative to atoms and ions with similar, but not filled/half-filled subshells in their
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