tossup #1–families and periods
Which element is a halogen in the third
period?
chlorine (Cℓ)
chemistry unit 6
review
bonus #1–atomic size trends
chemistry unit 6
review
Rank the size of a chlorine atom among F, Se,
Br, and Ne atoms. Arrange them smallest to
largest.
Ne < F < Cℓ < Br < Se
tossup #2–electron configuration
chemistry unit 6
review
What neutral element has electron
configuration
[Kr]
tin
50Sn
2
5s
10
4d
2
5p
bonus #2–categories
chemistry unit 6
review
Name a metalloid in the same family as tin.
Silicon (Si) and/or germanium (Ge).
Metalloids are at the boundary between
metals and non-metals, along the zig-zagging
dividing line.
tossup #3–ions
chemistry unit 6
review
What is the common stable ion of rubidium
(37Rb) and what is its complete electron
configuration?
Rb+: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6
Rb has 1 valence electron, therefore it normally
forms a +1 ion (by losing that one valence electron).
It then has 36 electrons (like Kr).
bonus #3–ion size trends
chemistry unit 6
review
Rank the sizes (from smallest to largest) of
Rb+ and the isoelectronic ions Sr+2 and Br–.
Briefly explain the reason for this ranking.
Sr+2 < Rb+ < Br–
38 p+ vs. 37 p+ vs. 35 p+
All have 36 electrons and a [Kr] configuration.
More protons attract the electron cloud more
strongly and decrease the ion's size.
tossup #4–valence electrons
chemistry unit 6
review
State the valence electron configurations of
both phosphorus and antimony (15P and 51Sb).
P:
Sb:
3s2 3p3
5s2 5p3
bonus #4–columns
chemistry unit 6
review
Give three different names for the column in
the periodic table that contains both
phosphorus and antimony (P and Sb).
column 5
group 5
nitrogen family
pnictogens
tossup #5–first ionization energy
chemistry unit 6
review
Which group 4 element has the greatest first
ionization energy?
carbon (C)
bonus #5–first ionization energy
chemistry unit 6
review
Given that lithium and carbon have first
ionization energies of 5.4 and 11.3,
respectively, estimate the ionization energies
for the rest of the period 2 elements.
[These are in units of eV.]
Li
Be
B
5.4
C
N
O
F
Ne
11.3
The ionization energies generally increase across
the period, but decrease slightly at groups 3 & 6.
Li
Be
B
C
N
O
F
Ne
5.4
9.3
8.3
11.3 14.5 13.6 17.4 21.5
tossup #6–valence electrons
Name the third-period element with six
valence electrons.
sulfur (S)
chemistry unit 6
review
bonus #6–successive ionization energies
If an element's atoms
have the ionization
energies shown at right,
what charge do its ions
usually have in nature
and what is the name of
that element's family?
chemistry unit 6
review
1st I.E.
2nd I.E.
3rd I.E.
4th I.E.
5th I.E.
6th I.E.
15.3 eV
28.7 eV
91.2 eV
157 eV
893 eV
1330 eV
This element would generally form +4 ions
and is in the carbon family.
Four easier ionizations indicate an atom with four valence electrons.
Carbon family elements have four valance electrons. Valence
electrons are easier to remove than core electrons.
tossup #7–atom and ion sizes
chemistry unit 6
review
Which is the smallest among the following
atoms and ions?
K,
Ca2+
+
K,
Ca,
2+
Ca
bonus #7–atom and ion sizes
chemistry unit 6
review
Choose the smallest in each of the following
pairs and explain why it is smaller.
K or Ca
+
K or
2+
Ca
Ca is smaller than K.
They have a similar valence electrons (1 or 2 in the 4s orbital), and
Ca's 20 protons attract the 4s electrons more strongly than K's 19
protons.
Ca2+ is smaller than K+.
They both have 18 electrons, and Ca's 20 protons attract the
electrons more strongly than K's 19 protons.
tossup #8–atom sizes
chemistry unit 6
review
Which is the largest atom among the
following?
Cℓ, Ar, Se, Br
Se
bonus #8–atom sizes
chemistry unit 6
review
Rank the following four elements from
smallest to largest and explain each
comparison separately.
Cℓ, Ar, Se, Br
Ar < Cl < Br < Se
Ar < Cl (both have a few valence electrons in the 3p orbital, but Ar
has one more proton than Cl, causing more attraction)
Cl < Br (both have 7 valence electrons, but Cl's are in the smaller 3p
orbital while Br's are in the larger 4p orbital)
Br < Se (as with Ar vs. Cl, Br has one more proton, thus it attracts
their similar 4p valence electrons more strongly than Se does)
tossup #9–electron configuration
chemistry unit 6
review
How will electrons be distributed in the
p-orbitals of any element in the oxygen
family?
Because one electron will go into each orbital
before any electrons pair, the four electrons in an
oxygen family element's p orbital would be
arranged:
↑↓
↑
↑
bonus #9–orbitals
chemistry unit 6
review
Describe how the four electrons in the
p-orbitals of an oxygen family element behave
in terms of the actual orbitals pictured below.
Two electrons would randomly zip around
inside both halves of one of the above
orbitals. Each of the other orbitals would have
one electron randomly moving through both
halves of it.
tossup #10–spectra
chemistry unit 6
review
Why are salts such as copper (II) nitrate and
strontium chloride mixed with the gunpowder
inside of fireworks?
Cu flame test
http://en.wikipedia.org/wiki/File:Flametest--Cu.swn.jpg
Many metal cations give off distinctive
colors of light when they are heated to
high temperature in a flame or other
reaction. [In this case, copper
produces green light and strontium
produces crimson red light.]
bonus #10–spectra
chemistry unit 6
review
Describe the general process by which an
atom produces a spectrum when heated or
subjected to high voltage.
an electron in the atom absorbs energy
that electron rises to a higher-energy orbital
later that electron returns to a lower-energy orbital
the excess energy that the electron loses is transferred to
a photon which carries the energy away as light (or other
electromagnetic radiation)

tossup #11–spectra
Suppose that due to the
transitions shown at right, an
element emits a spectrum
containing orange, violet,
and green light and infrared
radiation.
Which of these is the green
light?
6p to 3p is green
Ranking these four from least
to greatest energy:
infrared (4p to 3p)
orange (5p to 3p)
green (6p to 3p)
violet (7p to 3p)
chemistry unit 6
review
bonus #11–spectra
Given that these electron
transitions produce infrared,
orange, green, and violet
lines in the spectrum, what
electron transitions should
produce:
red light?
ultraviolet radiation?
red from e.g. 5s or 4d to 3p
(more energy change than IR,
less than orange)
UV from e.g. 7p to 2p
(more energy change than
violet)
chemistry unit 6
review
tossup #12–electron configuration
chemistry unit 6
review
What is the electron configuration of a neutral
iodine atom? (You may use shortcut
notation.)
[Kr] 5s2 4d10 5p5
bonus #12–families and periods
chemistry unit 6
review
Write the neutral formula of the salt formed by
reacting iodine with the alkaline earth metal in
the same period.
SrI2
tossup #13–first ionization energies
chemistry unit 6
review
Given that the first ionization energy for
calcium (Ca) is 590 kJ/mol, make reasonable
estimates of the first ionization energies of K
and Mg.
They should be in the order K < Ca < Mg.
(The real values are 419, 590, and 738
kJ/mol, respectively.)
bonus #13–successive ionization energies
chemistry unit 6
review
Given that the first ionization energy for
calcium (Ca) is 590 kJ/mol, make reasonable
estimates of the 2nd, 3rd, and 4th ionization
energies of Ca.
e.g. 590, 1200, 9000, and 12 000 kJ/mol
Each will be larger than the one before, and the 3rd I.E. will
be much higher than the first two. (This is because Ca has
two valence electrons; I.E. is modest for the valence
electrons but much higher for core electrons.)
tossup #14–atom and ion size
3–
Rank the sizes of Sb ,
smallest to largest.
Te < Te2– < Sb3–
chemistry unit 6
review
Te,
2–
and Te from
bonus #14–valence electrons
chemistry unit 6
review
Concerning their valence electrons, identify
what is similar about Se and Te and what is
different about them.
Both have six valence electrons arranged in an ns2np4
configuration.
But Te has those six electrons in the 5s and 5p orbitals,
which are larger and higher in energy than the 4s and 4p
orbitals where Se's valence electrons are.
tossup #15–electron configuration
chemistry unit 6
review
What is the electron configuration of bismuth,
83Bi?
[Xe] 6s2 4f14 5d10 6p3
bonus #15–electron configuration
chemistry unit 6
review
What is the electron configuration of gold,
79Au
(a) assuming that it “follows the rules”
(b) given that it “breaks the rules”
(a) [Xe] 6s2 4f14 5d9
(b) [Xe] 6s1 4f14 5d10
One electron has been “promoted” from 6s to 5d.
tossup #16–electron configuration
chemistry unit 6
review
Identify the ion that is isoelectronic with neon
and is:
a) a chalcogen
b) an alkali metal
a) oxide, O2–
b) sodium ion, Na+
bonus #16–electron configuration
chemistry unit 6
review
Write the neutral formula of the salt yttrium
selenide and compare and contrast the sizes
of the ions of which it is made.
Y2S3; Y3+ is smaller than Se2–
The expected ions are Y3+ and Se2– both of which have
electron configuration [Kr]. The neutral salt is thus
Y2S3, and the Y3+ ion (39 protons with 36 electrons)
should be considerably smaller than and Se2– (which
has only 34 protons for 36 electrons).