1. The document is a worksheet about periodic trends that contains questions asking students to order elements by atomic radius and ionization energy and identify which element has the highest melting point. 2. It also asks students to explain trends in atomic radius within groups, why some elements have higher ionization energies, and to identify an element based on its successive ionization energies. 3. The second part of the document provides clues to code letters that correspond to elements, asking students to place the code letters in the correct spots on a partial periodic table.

1. Name Period Date
Periodic Trends – Ch. 6
(p. 163-169)
1. Put the following elements in order from smallest to largest atomic radius and explain
why: C, O, Sn, Sr.
2. Put the following elements in order from lowest to highest first ionization energy and
explain why: Al, Ar, Cs, Na.
3. Which of the following elements most likely has the highest melting point – I, Mo, Te?
Explain why.
4. Explain how shielding contributes to the atomic radius trend within a group.
5. Why do magnesium, phosphorus, and zinc exhibit slightly higher first ionization
energies than the general trend within each of their periods?
6. Which element in the third period is best represented by the six successive ionization
energies listed below? Explain your reasoning.
1st IE 2nd IE 3rd IE 4th IE 5th IE 6th IE
577 1,815 2,740 11,600 15,000 18,310
Periodic Trends – Ch. 6-3 CHEM

2. Name Period Date
Periodically Puzzling
You have been given a list of code letters and clues that correspond to the representative elements
in the first four periods of the periodic table. Place each code letter in its proper space in the partial
periodic table below. NOTE: The code letters fall into these groups on the periodic table: JKQ,
WNVG, IAL, EPFZ, YBR, ODS, CXU, THM.
CODE CODE
CLUE CLUE
LETTER LETTER
V has largest ionization energy in its period. I has the smallest first ionization energy in its
group.
E is the largest atom in its period.
C has atoms that are larger than those of U,
U has1A
7 valence electrons in the second but smaller than those of X. 8A
energy level.
1 18
V has one more proton in its nucleus than U.
D has 5 valence electrons.
H has the largest first ionization energy in its
J 1 has 2 valence electrons.
2A 3A 4A 5A 6A
group. 7A
T 2 13
has 6 valence electrons in the fourth 14 15
G has two protons 17
16 in each atom.
energy level.
N has a full third energy level.
A 2 has 4 valence electrons in the second
energy level. J has valence electrons in the second energy
level.
R has an atomic number one less than A.
Q has an atomic mass greater than that of J
O 3 has an atomic number one more than A. and less than that of K.
S has 18 more protons in its nucleus than D. E has an atomic number less than that of Z
F has a single electron in the first energy but greater than that of P.
4 level. Z is the largest atom in its group.
Y has atoms that are larger than the atoms
of B.
Periodic Trends – Ch. 6-3 CHEM