06 Electron Configurations and Periodic Trends Online Quiz Questions

$\mathrm{[Ar] \, 3d^1}$

$\mathrm{[Ar] \, 4s^1}$

$\mathrm{[Ne] \, 3s^2 \, 3p^5}$

$\mathrm{[Ar] \, 4s^2}$

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Elements in the same main-group column have identical complete electron configurations.

An element's block is determined by the highest principal energy level it occupies.

The table's blocks reflect which subshell is being filled, and members of a main-group column have similar outer-electron configurations.

Elements in the same main-group column fill different subshell types in the same period.

A > C > B

B > A > C

C > B > A

C > A > B

Effective nuclear charge tends to fall because added electrons cancel the added protons completely.

Effective nuclear charge tends to rise because proton number increases while electrons are generally added to the same principal energy level.

Effective nuclear charge remains constant because shielding increases by exactly one unit for every added proton.

Effective nuclear charge tends to rise only because each step across a period adds a new principal energy level.

The leftmost element, because its outer electron is least shielded.

The leftmost element, because atomic radius generally decreases toward the right.

The rightmost element, because the stronger nuclear attraction generally makes electron removal harder.

Both elements have the same first ionization energy because they occupy the same principal energy level.

Boron is lower because its outermost electron is in a higher-energy 2p subshell than beryllium's 2s electron.

Boron is lower because its outermost electron occupies a lower-energy subshell than beryllium's.

Beryllium is lower because adding a proton always makes an electron easier to remove.

Their values must be equal because both atoms have electrons in the second principal energy level.

Atoms get smaller and ionization energies rise because the nucleus gains protons.

Atoms get larger and ionization energies rise because additional shells strengthen attraction to the outer electron.

Atoms get smaller and ionization energies fall because shielding eliminates nuclear attraction.

Atoms generally get larger and first ionization energies generally fall as outer electrons become farther away and more shielded.

A more positive value always means more energy is released.

A more negative value means more energy is released.

A value closer to zero means the atom gains an electron more strongly.

The sign has no meaning unless the atom is already an ion.

Fluorine's value is more negative because its smaller shell always attracts an added electron more strongly.

Their values must be identical because they are in the same group.

Chlorine's value is more negative because its roomier 3p shell has less electron–electron repulsion for the added electron than fluorine's compact 2p shell.

Chlorine's value is more negative because the added electron enters a filled subshell.

Its added electron begins a new subshell, pairs in an occupied orbital, or enters beyond a filled shell.

Its atomic radius is smaller than that of every element in the same period.

Its first ionization energy follows the general trend across the period.

Its inner electrons shield the nucleus from the added electron completely.

The Aufbau principle is invalid for every element in the d block.

Pauli's principle allows chromium and copper orbitals to hold more than two electrons.

Hund's rule alone determines the exact ground-state configuration of every element.

The simple filling order is a useful guide, but observed configurations for some elements can differ because subshell energy differences are small.

3p, 3d, 4s, 4p

3p, 4s, 3d, 4p

3p, 4s, 4p, 3d

3p, 4p, 4s, 3d

One 2p orbital has a pair; the other two are empty.

Two 2p orbitals each have a pair; the third is empty.

One 2p orbital has a pair; each of the other two has one electron.

Each 2p orbital has one electron, and the fourth electron enters a 3p orbital.

One orbital contains ↑↓; a second contains ↑; a third contains ↑.

Three equal-energy orbitals each contain one electron with spin ↑.

One orbital contains ↑↓; a second contains ↓; a third contains ↑.

One orbital contains ↑↑; a second contains ↑; a third is empty.

A block identifies the number of occupied energy levels, and a column identifies atoms with identical total electron counts.

A block reflects the type of subshell being filled, and elements in the same main-group column have similar outer-electron configurations.

A block groups elements by their first ionization energy, and a column groups elements by atomic radius.

A block identifies the number of valence electrons, and a column identifies the subshell filled most recently.

Protons are added while electrons are generally added to the same principal energy level, so effective nuclear charge tends to rise.

Protons are added, but each added electron occupies a new principal energy level, so shielding always cancels the added nuclear charge.

The number of protons stays fixed while electrons are added to the same energy level, so effective nuclear charge tends to fall.

Each added electron removes an inner electron, so the outer electrons experience less nuclear attraction.

Chlorine is generally larger because its greater nuclear charge always expands the electron cloud.

They are generally the same size because their outer electrons occupy the same principal energy level.

Sodium is generally larger because atomic radius tends to decrease from left to right across a period.

Sodium is generally smaller because it has fewer protons attracting its electrons.

Boron has a higher first ionization energy because every step to the right increases the energy required to remove an electron without exception.

Boron has a lower first ionization energy because its outermost electron is in the higher-energy 2p subshell rather than beryllium's 2s subshell.

Boron has a lower first ionization energy because its outermost electron occupies a new principal energy level.

Boron has a higher first ionization energy because its 2p subshell is completely filled.

Fluorine has the more negative value because a smaller atom always releases more energy when gaining an electron.

The values must be identical because fluorine and chlorine occupy the same group.

Chlorine has the more negative value because its added electron enters a compact 2p subshell with stronger repulsion.

Chlorine has the more negative value because its added electron enters a roomier 3p shell, where electron–electron repulsion is relatively lower than in fluorine's compact 2p shell.