Concept/Skills Development
“FAMILY RESEMBLANCE”
[Wolfgram, D. (1987, December). ChemMatters, p. 16.]
Can you place these elements in their proper positions on the Periodic Table without knowing their identity?
Instead of the usual chemical symbol, each element is represented by a code letter, and some clues to the element’s
identity are listed below. In addition, the elements fall into these families or groups:
JKQ, WNVG, IAL, EPFZ, YBR, ODS, CXU, THM
Place each code letter in its proper space in the table below, then indicate the actual chemical symbol that
corresponds to each letter.
W
P
X
D
is an inert gas.
is an alkali metal.
is a halogen.
is an element that needs three electrons to
become stable.
K is an atom that readily yields a 2+ ion.
M is an element found in the group to the right of S.
B would probably form a 3+ ion.
A has six protons in its nucleus.
R has an atomic number one less than A.
O has an atomic number one more than A.
S has 18 more protons in its nucleus than has D.
F has only one proton in each atom.
Y has atoms that are larger than the atoms of B.
I has the largest atomic number in its group.
1
2
T
C
is found in the fourth period (or row).
has atoms that are larger than those of U, but
smaller than those of X.
V has one more proton in its nucleus than U.
H has the smallest atomic number in its group.
G has two protons in each atom.
N is a third period element.
J is a second period element.
Q has an atomic mass greater than that of J and
less than that of K.
E has an atomic number less than that of Z but
greater than that of P.
Z has more protons than other elements in its
group.
U is found in the second period.
13 14 15
16 17 18
H
Li Be
He
B C N
Na Ms
O
F
Al Si
Ne
K Ca
Ga Ge A P S Cl Ar
s Se Br
Kr
Answers to Family
Resemblance:
F = H; G = He; P = Li; J = Be;
R = B; A = C; O = N; H = O;
U = F; V = Ne; E = Na; Q = Mg;
B = Al; L = Si; D = P; M = S;
C = Cl; N = Ar; Z = K; K = Ca;
Y = Ga; I = Ge; S = As; T = Se;
X = Br; W = Kr.
Periodicity (PERD)
31
Worksheet: Periodic Table Trends
Name___________________
For each of the following, circle the correct element.
Li
Si
S
metal
N
P
As
smallest ionization energy
K
Ca
Sc
largest atomic mass
S
Cl
Ar
member of the halogen family
Al
Si
P
greatest electron affinity
Ga
Al
Si
largest atomic radius
V
Nb
Ta
largest atomic number
Te
I
Xe
member of noble gases
Si
Ge
Sn
4 energy levels
Li
Be
B
member of alkali metals
As
Se
Br
6 valence electrons
H
Li
Na
nonmetal
Hg
Tl
Pb
member of transition metals
Na
Mg
Al
electron distribution ending in s2p1
Pb
Bi
Po
metalloid
B
C
N
gas at room temperature
Ca
Sc
Ti
electron distribution ending in s2d2
CHEMISTRY: A Study of Matter
© 2004, GPB
4.14
Worksheet: Periodic Table Puzzles
Name___________________
Fictitious symbols are used for the first 18 elements in the periodic table. Use the clues below to
write the fictitious symbol in the appropriate spot on the periodic table provided. Symbols for real
elements do not represent those elements. HINT: You do not have to complete each clue in order.
1
18
2
13
14
15
16
17
Clue 1
U and J are alkali metals. J has more energy levels.
Clue 2
T has 4 valence electrons on the 3rd energy level.
Clue 3
M is a metal in period 3 with 2 valence electrons.
Clue 4
X has one proton in its nucleus.
Clue 5
Q has 2 energy levels, is a nonmetal, and is a solid at room
temperature.
Clue 6
L is a noble gas that doesn’t have 8 valence electrons.
Clue 7
Z and Y are members of the nitrogen family. Y is a gas at room
temperature.
Clue 8
D has an ending electron distribution of s2p5. R has an ending electron
distribution of s2.
Clue 9
G has 6 valence electrons.
Clue 10
V and W have full outer energy levels. V has 3 energy levels.
Clue 11
A atoms have 3 valence electrons and E atoms have 6 valence
electrons. Both are in the second period.
Clue 12
K has one fewer total electrons than V.
Clue 13
I has 3 valence electrons on the third energy level.
CHEMISTRY: A Study of Matter
© 2004, GPB
4.8
Fictitious symbols are used for the first 18 elements in the periodic table. Use the clues below to
write the fictitious symbol in the appropriate spot on the periodic table provided.
HINT: You do not have to complete each clue in order.
1
18
2
13
14
15
16
17
Clue 1
Lg has 5 valence electrons on the second period.
Clue 2
Eg atoms have 12 protons in the nucleus.
Clue 3
Qp and Ju are halogens. Ju has fewer energy levels.
Clue 4
Ke is a member of the oxygen family. Ke is in the same period as Lg.
Clue 5
Gn is a member of the nitrogen family.
Clue 6
Rm and Sk have 3 valence electrons. Rm has more occupied energy
levels than Sk.
Clue 7
Td and Vo are metals in the same family. Vo has 2 energy levels and
Td has 3 energy levels.
Clue 8
Wa is a member of the alkaline earth metals.
Clue 9
Zy has an ending electron distribution of 3p4. An has 18 total
electrons.
Clue 10
Ms is a nonmetal located on the side of the periodic table with all of
the metals.
Clue 11
Bx atoms and Oz atoms are stable. Oz atoms are heavier than Bx
atoms.
Clue 12
Ds and Cy are members of the carbon family. Ds has fewer protons
than Cy.
CHEMISTRY: A Study of Matter
© 2004, GPB
4.9
Periodic Trends Practice
Standard
a. Use the Periodic Table to predict periodic trends including atomic radii, ionic radii, ionization energy, and electronegativity of various elements.
b. Compare and contrast trends in the chemical and physical properties of elements and their placement on the Periodic Table.
SCb: Use the orbital configuration of neutral atoms to explain its effect on the atom’s chemical properties
1. Circle which element has the larger atomic radius:
Choice 1
Choice 2
Choice 1
Choice 2
K
Br
Al
Cl
Na
Mg
Mg
Al
Fr
F
Ca
Cs
Li
Ca
N
Br
I
Br
Ga
K
2 Circle which element has the larger atomic radius:
Choice 1
Choice 2
Choice 3
Choice 1
Choice 2
Choice 3
Cl
Br
S
At
Po
Uuh
Na
Mg
K
Mg
Al
Ga
Fr
F
Rh
Ca
Cs
Hf
Li
Na
K
N
P
S
I
Br
Te
W
Ta
Sg
3. Circle which element has the larger Ionization Energy:
Choice 1
Choice 2
Choice 1
Choice 2
K
Br
Al
Cl
Na
Mg
Mg
Al
Fr
F
Ca
Cs
Li
Ca
N
Br
I
Br
Ga
K
4 Circle which element has the larger Ionization Energy:
Choice 1
Choice 2
Choice 3
Choice 1
Choice 2
Choice 3
Cl
Br
S
At
Po
Uuh
Na
Mg
K
Mg
Al
Ga
Fr
F
Rh
Ca
Cs
Hf
Li
Na
K
N
P
S
I
Br
Te
W
Ta
Sg
5. Circle which element has the larger Electronegativity:
Choice 1
Choice 2
Choice 1
Choice 2
K
Br
Al
Cl
Na
Mg
Mg
Al
Fr
F
Ca
Cs
Li
Ca
N
Br
I
Br
Ga
K
6 Circle which element has the larger Electronegativity:
Choice 1
Choice 2
Choice 3
Choice 1
Choice 2
Choice 3
Cl
Br
S
At
Po
Uuh
Na
Mg
K
Mg
Al
Ga
Fr
F
Rh
Ca
Cs
Hf
Li
Na
K
N
P
S
I
Br
Te
W
Ta
Sg
7. Circle which element or ion has a larger radius:
choice 1
choice 2
choice 1
choice 2
+
Na
Na
Cl
Cl-1
Mg
Mg+2
Cl-1
S
2-
F
+
Li
2-
F-
-1
O
O
Cl
2-
O
O
+
Na
Mg
Li
2+
O
8 Circle which element or ion has a larger radius:
Choice 1
Choice 2
Choice 3
Choice 1
Choice 2
Choice 3
Pb
Sn4+
Al2+
Ga
Ca
Cs
Ba2+
Na
+
Na
Cl
Bi
Na+
Mg
O2-
Mg
-
Fr
+
3+
2+
Fr
F
Li+
Na+
K+
N3-
P
S2-
I
Br-
Te2-
Mg2+
Al
Cl-
9. Which element is the most electronegative? Why?
10. Which element is the least electronegative? Why?
11. When they constructed the modern periodic table, did they have gaps or did they know every element? Why were they able to
predict what would fill the gaps? (Use your book to help you with this answer.)
High School Chemistry Core Concept Cheat Sheet
The Periodic Table
Key Chemistry Terms
•
•
•
•
•
•
•
•
•
•
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Periodicity, Atomic Mass & Atomic Radii
Periodic Table: Tool for organizing the elements
Periods: Rows on the periodic table
Groups: Columns on the periodic table
Periodicity: Predictable patterns and trends on the
periodic table
Atomic Number: Number of protons in an atom. Defines
the element. Periodic table is organized in increasing order
of atomic number
Atomic Mass: mass in grams of 1 mole of atoms (6.02 x
1023 atoms)
Atomic Radius: Half the distance between two nuclei of
the same element when bonded together
Electronegativity: Pull an atom has on the shared
electrons in a bond with another atom.
Ionization Energy: Energy required to remove the
outermost electron from an atom.
Electron Affinity: Energy released when another electron
is added to an atom.
Ion: Atom with a charge
Cation: Positively charged ion. Results from loss of
electrons.
Anion: Negatively charged ion. Results from gain of
electrons.
Reading the Periodic Table
Most periodic tables give the following information
(although it may be in a different order):
Atomic #
12
Symbol
C
Name
Carbon
Atomic Mass
12.01
Important Regions of the Periodic Table:
1 2
4 5
3
6
7
Metals
Non-metals
Atomic Mass
Æ a period:
Subatomic particles are being added. This causes atomic
mass to increase
↓ a group:
Subatomic particles are also being added. This causes mass
to increase
Atomic Radii
Æ a period:
# of protons and electrons increase, increasing the “pull”
between the nucleus and the electrons. Radii decreases.
↓ a group:
# of protons and electrons increase, but the electrons are
added in a new electron shell. The new electrons are
“shielded” by the inner electrons from the pull of the nucleus.
Radii increases
Relationship Between Radii and Other Properties
Æ a period:
As radii decreases:
The electrons are closer to the nucleus and therefore feel the
“pull” more strongly.
Electronegativity, ionization energy and electron affinity
increase.
↓ a group:
As radii increase:
The electrons are farther from the nucleus and therefore are
more “shielded” by inner electrons from the pull of the
nucleus.
Electronegativity, ionization energy and electron affinity
decrease
Ionic Radii
Radii when forming a cation:
Loss of electrons. There are now more protons than
electrons. The pull of the protons on each electron is greater.
Cations have smaller radii than their parent atom.
Radii when forming an anion:
Gain of electrons. There are less protons than electrons. The
pull of the protons on each electron is less.
Anions have larger radii than their parent atom.
Metalloids
1. Alkali Metals
2. Alkaline Earth Metals
3. Transition Metals
4. Halogens
5. Nobel Gases
6. Lanthanides
7. Actidines
8 tall columns = main groups or representative elements
Memorizing the First 20 Elements
Use a Mnemonic to remember the symbols of the first
20 elements in order:
Happy Henry, the Little Beach Boy, CaN dO FiNe; Naughty
Megan, the Alpine Sister, Pretends to Ski at ClArK
Canyon.
ChemistrySurvival.com
Examples
List Li, Cs and K in order of increasing:
Radii: Li < K < Cs (radii increases ↓ a group)
Electronegativity: Cs < K < Li (decreases as radii
increases)
Ionization Energy: Cs < K < Li (decreases as radii
increases)
Electron Affinity: Cs < K < Li (decreases as radii increases)
List Ca+2, Ca and Ca1+ in order of increasing radii:
Ca2+ < Ca1+ < Ca
(Each time an electron is lost, a charge of +1 is added. As
electrons are lost, there is a higher ratio of protons : electrons
and radii decreases)
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How to Use This Cheat Sheet: These are the keys related this topic. Try to read through it carefully twice then recite it out on a
blank sheet of paper. Review it again before the exams.
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