Unit 8

Question 1

Spin quantum number (ms)

Answer 1

A quantum number that describes the magnetic properties of a particle; takes on the values +/-1/2 for an electron

Question 2

“up” electron spin

Answer 2

+1/2

Question 3

“down” electron spin

Answer 3

-1/2

Question 4

orbital energy-level diagram for a multi-electron atom/ion

Answer 4

the orbital energies of a multi-electron atom/ion depend upon both n and l (one-electron energy-level diagrams depend only on n). Orbital energies are greatly affected by inter-electron repulsions.

Question 5

electronic state

Answer 5

includes the full description of all 4 quantum numbers (n, l, ml, ms), often abbreviated with an electron configuration

Question 6

electron configuration

Answer 6

-the description of the distribution of electrons in atomic subshells and thus includes only quantum numbers n and l
-ex. an electron configuration 1s(2)2s(1) gives the n and l descriptions of the subshells 1s and 2s and the superscripts “1” or “2” indicate how many electrons are described by the orbitals of that particular subshell

Question 7

subshell

Answer 7

-A group of orbitals in an atom with the same energy
-group of orbitals with same n and l values (ex. 3d)

Question 8

orbital

Answer 8

-a function describing the location and wave-like behavior of an electron in an atom
-a three dimensional description of the most likely location of an electron around an atom
-all electrons with same n, l, ml values (ex. 3d(1))

Question 9

shell

Answer 9

-A group of subshells in the electron configuration of an atom that have similar energies
-all electrons with the same value of n (ex. 3s, 3p, 3d)
-an orbit that electrons follow around an atom’s nucleus

Question 10

Order of subshells

Answer 10

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Question 11

Pauli Exclusion Principle

Answer 11

-no two electrons in an atom may have the same set of quantum numbers; more specifically (n, l, ml, ms), two electrons with the same spin may not occupy the same spatial orbital
-violation of this principle is impossible and would result in forbidden configuration

Question 12

Ground Configuration Rule

Answer 12

-orbital subshell filling occurs in such a way as to allow the lowest total energy possible
-total energy of the atom/ion is the sum of the individual energies of each orbital associated with each of the electrons
-all lower subshells must be filled before higher subshells can have electrons
-when this rule is violated, it leads to excited configuration

Question 13

Hund’s Rule

Answer 13

-when electrons are added to orbitals of equal energy, they will half-fill every orbital, with the spins remaining parallel, before pairing in any orbital
-electronic states with the larger total spin (S) are energetically more stable
-requires assessment of ms values
-S= abs. value of sum of all ms values in configuration
-when Hund’s rule is violated, it results in higher energy state and thus an excited level for atom/ion
-2 electrons may occupy same orbital (m, l, ml) but must have different ms values (+/-1/2)

Question 14

Aufbau Principle

Answer 14

-summarizes the rules regarding ground electronic states
-asserts that the electronic states of elements may be built up one-by-one by successive additions of electrons to available orbitals in the correct sequence by following Pauli, Ground, and Hund’s
-not specific enough for quizzes/exams

Question 15

p-block element

Answer 15

An element that arises with the filling of a p orbital in the building up of the periodic table (groups 13-18 on PT)

Question 16

s-block element

Answer 16

An element that arises with the filling of an s orbital in the building up of the periodic table (groups 1+2 on PT)

Question 17

d-block element

Answer 17

An element that arises with the filling of a d orbital in the building up of the periodic table (groups 3-12 on PT)

Question 18

f-block element

Answer 18

An element that arises with the filling of a f orbital in the building up of the periodic table (bottom two rows on PT)

Question 19

atom/ion’s total energy

Answer 19

quantized, the sum of all electron energies

Question 20

ground electronic state

Answer 20

the electronic state that minimizes total energy

Question 21

excited state

Answer 21

occurs if electronic state violates Hund’s or Ground State Rule

Question 22

Electron configurations for transition metals

Answer 22

-use noble gas abbreviation to represent an atom/ion’s core electrons
-ex. Ti: [Ar]4s(2)3d(2)

Question 23

core electrons

Answer 23

electrons in the innermost filled rows

Question 24

valence electrons

Answer 24

electrons in the outermost row

Question 25

Element exceptions to electron configuration rules

Answer 25

-Cr, Mo, Cu, Ag, Au
-Cr and Mo prefer to have half-filled d orbitals and 1 s-electron
-Cu, Ag, and Au prefer to have filled d orbitals and 1 s-electron

Question 26

Rules for element exceptions to electron configuration

Answer 26

-Cr: [Ar]4s(1)3d(5)
-Mo: [Kr]5s(1)4d(5)
-Cu: [Ar]4s(1)3d(10)
-Ag: [Kr]5s(1)4d(10)
-Au: [Xe]6s(1)4f(14)5d(10)

Question 27

Ground Electron Configurations for ions

Answer 27

-Cations: remove electrons from the highest energy orbital
-Anions: add electrons to the lowest energy orbital available
-Transition metal cations: follow rule for cations (remove ns-electrons before removing (n-1)d-electrons)

Question 28

Radial Probability Density Plots

Answer 28

-4πr^2 x R^2(r)
-as n increases, distribution shifts outwards and electron is most likely to be found farther from nucleus (mpd, most probable distance)
-for orbitals with n>1, there will be nodes (RN= n-l-1)