Chapter 5 Flashcards
Ionization energy
minimum energy required to remove one electron from an atom in its ground state
True or False? It is easier to remove an electron from a cation.
False. It is harder.
True or False? The total number of electrons in an atom affects the ionization energy.
True
True or False? An electron in a multielectron atom is attracted to the nucleus, but repelled by the other electrons.
True
Screening
electron-electron repulsion cancels out some of the nuclear-electron attraction; electrons are primarily screened by inner electrons
Pauli Exclusion Principle
each electron has a unique set of four quantum numbers (n, l, ml, ms)
Aufbauf Principle
fill in orbitals starting with lowest energy orbital
Hund’s rule
most stable configuration is the one with the maximum number of electrons with the same spin
Write the electron configuration for Na.
[Ne] 3s1
Core electrons vs valence electrons
valence electrons: have highest principle quantum number plus partially filled d and f orbitals
core electrons: all the rest
Write the electron configuration for Ge2+.
[Ar]4s2 3d10
Write the electron configuration for Cu-
[Ar] 4s2 3d10
What happens to the atomic radius when electrons are added to an atom?
the atom gets bigger
Put the following in order from biggest to smallest atomic radius.
Na+ , Ne, O2-, F-, Mg2+
O2-, F-, Ne, Na+, Mg2+
Lattice energy
the energy released when an ionic solid decomposes into gaseous ions ; a measure of the attractive force holding those ions together
What happens to lattice energy when the charge on ions increases?
increases
What happens to lattice energy when size of atoms increases?
decreases
Paramagnetic vs diamagnetic
paramagnetic: unpaired spins; attracted to magnetic field
diamagnetic: paired spins; repelled by magnetic field
Give the chemical symbol for the element with the following ground-state electron configuration.
[Ne] 3s2 3p3
P
Nonmetals gain electrons under certain conditions to attain a noble-gas electron configuration. How many electrons must be gained by the element O?
2 electrons
Which noble gas electron configuration is attained in the element O gaining two electrons?
neon
The effective nuclear charge, Zeff, for a valence electron can be approximated using the core charge of the atom, that is, the total charge of the nucleus and the inner electrons. determine the core charge for an atom of Cl.
nuclear charge= +17
core negative charge = -10
total electrons - valence electrons = core charge
(+17) + (-10) = +7
Give the complete electron configuration for Br.
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5
Identify the number of core electrons for the following atoms:
a) Ar
b) Be
c) F
total electrons - valence electrons = core charge
a) 18-8=10
b) 4-2=2
c) 9-7=2
Most transition metal cations are paramagnetic, but there are some exceptions. Identify which of these first-series transition metals could form diamagnetic cations with charges of +3 or less, and which are paramagnetic.
Mn, Ni, Cu, Ti, Sc, Cr, Co, Fe, V, Zn
diamagnetic: Sc, Cu, Zn
paramagnetic: Ti, V, Cr, Mn, Fe, Co, Ni
For each atom or ion below, determine the number of unpaired electrons.
a) Ni2+ b) V2+ c) Fe d) As
a) [Ar] 4s2 3d8 2 electrons b) [Ar] 4s2 3d3 3 electrons c) [Ar] 4s2 3d6 4 electrons d) [Ar] 4s2 3d10 4p3 3 electrons
What is the electron configuration for Ga?
[Ar] 4s2 3d10 4s1
Give the full electron configuration for Al.
1s2 2s2 2p6 3s2 3p1
Arrange these elements according to atomic radius from largest to smallest.
Cl, Al, Ar, Na, Mg, Si, P, S
Na, Mg, Al, Si, P, S, Cl, Ar
Rank the following ions from largest to smallest ionic radius.
Rb+, Y3+, Se2-, Mo6+, Br-
Se2-, Br-, Rb+, Y3+, Mo6+
Describe the charge distribution (electronegativity) in OF2.
O is delta +
F is delta -
Rank these elements according to first ionization energy from highest to lowest.
Sn, C, Ge, Si
C, Si, Ge, Sn
Based on ion sizes, rank these compounds according to their expected lattice energy, from greatest to least.
NaCl, NaBr, NaF, NaI
NaF, NaCl, NaBr, NaI
How does the electron affinity of the single charged cation Na+ relate to the ionization energy of the neutral atom?
The electron affinity of Na+ is the same magnitude as the ionization energy of Na, but has the opposite sign.
Rank the following ions by their ionic radius from largest to smallest.
P3-, Ca2+, Cl-, K+, S2-
P3-, S2-, Cl-, K+, Ca2+
Rank the following by the most to least electronegative.
Al, O, C, Rb, Na
O, C, Al, Na, Rb
What is the ground state configuration for I-?
[Kr] 5s2 4d10 5p6
Which one of the following is expected to be repelled by a magnetic field?
a) F
b) Ca2+
c) N
d) Al
e) Mg+
b) Ca2+
Arrange the following in order of decreasing atomic radius:
Cl- , K+, Cl, Br-
Br-, Cl-, Cl, K+
List B, Ca, and Rb from easiest to most difficult to ionize.
Rb, Ca, B
Which of the following form an isoelectronic group?
a) Ge, As, Se
b) I-, Xe, Cs+
c) Br, Kr, Se2-
d) O, S, Se
e) N3-, P3-, As3-
b) I-, Xe, Cs+
The lattice energies for NaF, NaBr, NaI and Na2O are 910, 732, 682, and 2481. Which of the following is most likely the lattice energy for NaCl?
a) 595
b) 769
c) 940
d) 1051
e) 1700
b) 769
Which one of the following species has the most unpaired electrons?
a) S
b) Si
c) Al
d) S2-
e) F
a) S
b) Si
Provide the ground state electron configuration for Br+ and write 4 valid sets of quantum numbers for only the valence p electrons.
[Ar] 4s2 3d10 4p4
n=4, l=1, ml= -1, ms= 1/2
n=4, l=1, ml= -1, ms= -1/2
n=4, l=1, ml=0, ms= 1/2
n=4, l=1, ml=+1, ms= 1/2
