CHEMISTRY 11 AP – PERIODIC TABLE TRENDS WORKSHEET
1) Circle which member of each of the following pairs would you expect to have a larger atomic
radius?
(a)
Sb
or
P
(b)
Ca
or
Co
(c)
O
or
S
(d)
Li
or
N
(e)
F
or
S
(f)
B
or
Si
(g)
Cr
or
W
(h)
Cl
or
Br
2) Circle which member of each of the following pairs would you expect to have a smaller atomic
radius?
(a)
Mg
or
P
(b)
C
or
Si
(c)
Pb
or
Bi
(d)
Ba
or
Y
(e)
K
or
Sr
(f)
Li
or
Fr
(g)
Ag
or
Mo
(h)
N
or
P
3) Circle which member of each of the following pairs is expected to be larger?
(a)
Na+
or
Na-
(b)
I
or
I+
(c)
As
or
As3-
(d)
Na+
or
Cs+
(e)
Se-
or
S
(f)
S2-
or
S
(g)
Fe2+
or
Co3+
(h)
Au+
or
Ag+
(i)
Li2+
or
He
(j)
Na+
or
O2-
(k)
Fe2+
or
Fe3+
(l)
Cl-
or
F-
4) Arrange the following (Br-, Kr, Sr2+, Rb+, Se2-) in order from:
Largest atomic radius
Smallest atomic radius
Sr2+
Rb+
Kr
Br-
Se2-
5) Circle which member of each of the following pairs is expected to be smaller?
(a)
Ca2+
or
Se2-
(b)
O2-
or
S2-
(c)
K+
or
Cl-
(d)
Cl
or
Se-
(e)
Cs+
or
La3+
(f)
Br-
or
Br
(g)
V
or
V4+
(h)
Ag+
or
Cd2+
(i)
Cu+
or
Cu2+
(j)
Cl-
or
S2-
(k)
O
or
O2-
(l)
Bi3+
or
Pb2+
6) Circle which member of each of the following pairs should have greater ionization energy?
(a)
Br
or
Cl
(b)
Al
or
Cl
(c)
Ne
or
Xe
(d)
Mg
or
Ba
(e)
F
or
Ne
(f)
Rb
or
I
(g)
Al
or
Sn
(h)
O
or
Pb
7) Circle which member of each of the following pairs should have lower ionization energy?
(a)
N
or
P
(b)
S
or
Cl
(c)
Mg
or
Ti
(d)
Al
or
Mo
(e)
Na
or
F
(f)
Br
or
Xe
(g)
C
or
Ga
(h)
Na
or
Sr
8) Using only the Periodic Table, rank each of the following elements in order of increasing first
ionization energies.
(a) Ar, Cl, P, Na, Si
Na < Si < P < Cl < Ar
(b) Sb, As, Bi, N, P
Bi < Sb < As < P < N
(c) Al, Ar, Cs, Mg, Rb, Si, Na, S
Cs < Rb < Na < Mg < Al < Si < S < Ar
9) What role do inner or core electrons play in determining atomic size and ionization energy?
Inner or core electrons are effective at shielding the outer electrons from the attractive force of the
nucleus and exerting a repulsive force on those outer clouds of electrons. As the extent of that
shielding increases, which occurs when descending a chemical family, the atomic size increases and
the ionization energy decreases.
10) Consider the first two ionization energies for lithium:
IE1 = 519 kJ/mol
IE2 = 7,285 kJ/mol
Explain why lithium’s second ionization energy is more than 10 times its first.
Lithium’s electron configuration is 1s2 2s1. Lithium’s single valence electron is shielded from the
nuclear charge by the inner or core 1s2 electrons. It is therefore relatively easy to remove that outer
electron and so we see that the first ionization energy is low. After that electron is removed
however, the next electron removed is an inner core electron, which is not shielded at all from the
nuclear charge. As a result, lithium’s second ionization energy is approximately 14 times greater
than the first ionization energy.
11) Based on the data below, element X is in which group of the Periodic Table? Explain.
Ionization Energies for Element X (kJ/mol)
IE1
IE2
IE3
IE4
IE5
540
1,651
2,650
14,921
17,345
Since the largest energy gap is from the third to fourth ionization energy, element X must achieve
noble gas configuration after losing 3 electrons therefore it would be in group 13 on the Periodic
Table.
12) Circle which member of each of the following pairs should have greater electronegativity?
(a)
F
or
I
(b)
Rb
or
Li
(c)
Si
or
Cl
(d)
Na
or
Si
(e)
Sn
or
S
(f)
N
or
Sb
(g)
B
or
Pb
(h)
Fe
or
W
13) Circle which member of each of the following pairs should have lower electronegativity?
(a)
Mg
or
S
(b)
K
or
Mn
(c)
As
or
S
(d)
Cl
or
I
(e)
C
or
Sb
(f)
Cr
or
N
(g)
Be
or
Rb
(h)
B
or
Bi
14) Elements with low ionization energies tend to have relatively low electronegativities. What might
this indicate about how they will behave when reacting with high IE and EN elements?
When such reactions occur, elements with low ionization energies and low electronegativities will
tend to lose valence electrons to elements whose ionization energies and electronegativities are
high.
15) Elements with high ionization energies tend to have relatively high electronegativities. What might
this indicate about how they will behave when reacting with low IE and EN elements?
When such reactions occur, elements with high ionization energies and high electronegativities will
tend to gain valence electrons from elements whose ionization energies and electronegativities are
low. The results of the reactions described in questions 14 and 15 will be the formation of cations
by atoms losing valence electrons and the formation of anions by atoms gaining valence electrons.
16) What do you think might occur if two non-metal atoms, each with high EN and IE values reacted
together?
When two non-metal atoms, each with relatively high ionization energies and electronegativities
react, as both attract their valence electrons strongly and neither have a tendency to lose them, they
are likely to form bonds by sharing valence electrons rather than by transferring them.