Leader: Sara
Course: Chem177D
Instructor: Bonaccorsi
Supplemental Instruction
Date: 10/23/13
Iowa State University
1) Effective Nuclear Charge: the net positive charge experienced by an electron in
a many-electron atom. What is the equation?
Zeff = N – S
Worksheet 7A:
Periodic Table
2) Arrange the following atoms in order of increasing effective nuclear charge of the
valence electrons:
Na
Al
Mg
Si
Cl
Ar
S
Na
Mg
Al
Si
S
Cl
Ar
3) Show the Zeff trend on the periodic table:
Smaller Z eff
4) What atom has the LARGEST atomic radius?
Francium
5) What atom has the SMALLEST atomic radius?
Helium
6) Show the atomic radius trend on the periodic table:
Larger Z eff
Smallest radius
Largets radius
7) If the charge of an atom changes, does the radius of the atom change?
Yes
Positive is smaller, Negative is larger
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8) Rank the following in order of size smallest to largest:
a. Te
S
O
Po
Se
O
S
Se
Te
Po
b. Ra
O
Ca
P
P
Ga
Ga
Ca
Fr
Ra
O
Fr
9) Which is larger?
a. Mg
or
Mg2+
b. Al
or
Al3+
c. I
or
I-
d. K
or
K+
e. Se
or
Se2-
f. Cl-
or
Br-
g. F-
or
Ne
h. N3-
or
P3-
10) What is isoelectronic?
Elements/ ions with the same number of electrons
11) Put the following in order of increasing radius:
BrSe2- Sr2+ Kr
Rb2Se
Br
Kr
Rb
Sr2+