7.2: Atomic Subshell Energies and Electron Assignments
- Page ID
- 169579
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)The Aufbau Process
Exercise \(\PageIndex{1}\)
The procedure by which electrons are assigned to (or built up into) orbitals is known as the ____ principle.
a. Aufbau b. Bohr c. Planck d. Hund e. Pauli
- Answer
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a. Aufbau
Exercise \(\PageIndex{2}\)
Which of the following statements is true concerning the electron configuration [Xe]6p2?
- This configuration cannot be the ground-state electron configuration for a Ba atom because it violates the Pauli exclusion principle.
- This configuration cannot be the ground-state electron configuration for a Ba atom because it violates Hund's rule.
- This configuration is the ground-state electron configuration for a Ba atom.
- This configuration cannot be the ground-state electron configuration for a Ba atom because it violates the Heisenberg uncertainty principle.
- This configuration cannot be the ground-state electron configuration for a Ba atom because it violates the Aufbau principle.
- Answer
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e. This configuration cannot be the ground-state electron configuration for a Ba atom because it violates the Aufbau principle.
Exercise \(\PageIndex{3}\)
According to the Aufbau principle, which of the following subshells is typically filled next after the 4s subshell?
a. 3d b. 4s c. 3p d. 2p e. 2s
- Answer
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a. 3d
Exercise \(\PageIndex{4}\)
Which of the following statements is/are CORRECT for an oxygen atom?
- The effective nuclear charge felt by a 2s electron is greater than that felt by a 1s electron.
- The effective nuclear charges felt by 2s and 2p electrons are identical.
- The effective nuclear charge felt by a 2p electron is less than that felt by a 2s electron.
a. 1 only b. 2 only c. 3 only d. 1 and 3 e. 1, 2, and 3
- Answer
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c. 3 only
Exercise \(\PageIndex{5}\)
The small, but important, energy differences between 3s, 3p, and 3d electrons is a consequence of
- the number of electrons they can hold
- their principal quantum number
- the Heisenberg uncertainty principle
- thier effective nuclear charge
- Hund's rule
- Answer
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d. thier effective nuclear charge
Exercise \(\PageIndex{6}\)
Which of the following statements is true?
- Outer electrons efficiently shield one another from nuclear charge.
- Core electrons effectively shield outer electrons from nuclear charge.
- Valence electrons are the most difficult of all electrons to remove.
- Core electrons have the lowest ionization energies of all electrons.
- Valence electrons in the outermost shell of all elements have the highest ionization energy.
- Answer
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b. Core electrons effectively shield outer electrons from nuclear charge.