Block:________
Name:
Chemistry 11
Date:_______________
Trends Activity
Assignment
Atomic Radius: the distance from the center of the nucleus to the outer most electrons in an
atom.
Ionic Radius: the distance from the center of the nucleus to the outer most electrons in an ion.
Ionization Energy: the energy needed to remove an electron.
First ionization energy is the energy needed to remove the first electron from an
atom. The first ionization energy is always the lowest.
Electronegativity: the ability to attract an electron in a chemical bond.
Most commonly measured with the Pauling Scale, where 0 represents the least
ability and 4 is the greatest ability to attract electrons in chemical bonds.
Electron Affinity: the energy change associated with gaining an electron.
Effective Nuclear chargelZeff): a measure of the pull of the protons in the nucleus on the valence
electrons in an atom/ion.
Zeff = atomic number shielding electrons
Note: shielding electrons for our purposes are the inner electrons that block some
of the pull of the nucleus on the electrons that are farther out.
—
Example: Oxygen
Zeff = atomic number
Zeff = 82
Zeff = +6
—
shielding electrons
Use the provided periodic table to answer the questions below.
1. a) As you go from hydrogen down a column, what happens to the
dius?
Increases ecreases
b) Draw Bohr diagrams for hydrogen, lithium and sodium. Calculate the effective nuclear
charge for each atom and use this information to explain the atomic radius trend.
ac- cYn-
QcQ
k’Ls
OI\&
y1
cc-kQ- ç)
rnôce
Icic tm
€Lcn ckk,
i4& scici
G(
2. a) As you go from lithium across a row what happens to the atomic radius?
(
b) Draw Bohr diagrams for lithium, beryllium and boron. Calculate the effective nuclear
charge for each of the three elements and use these values to explain the atomic radius
trend.
çç
nccecs Cifc
r-ec Xe&n Th doc, rrv-kkinc
What unit is ionization energy measured in? k (k’o 3&
TR.
3.
,c \icc ci-
ftri3S
-QSc’
4. a) As you go from hydrogen down a column, what happens to the ionization ener es?
Increase ecreases
b) Using your Bohr diagrams from question #1, explain this trend.
V
Tk. ‘io.kn
OV
iN
oe
e\ec
esS
4c2kQ5z.
coc
ies erc
ucJis
m
(\ bs ccc
rCc-p
4
c
C
4
C
C
D
C-.
2
ci)
>
..
j I
ot
.;
.
;
ci)
cCc-i). i) I LL
ci)
-d
ci)
C4
o
0)
0-’
.1
H
C
E
(
I
Cl)
-
.b
rJ)
+=.
ci)
ci
.ci)
Cl)
ci
0.)
44
C
Cl)
Cl)
a)
4
C
0
—
0
>-.
C)
•;s
—
>..
0
Cl)
V
--)
ci)
.
.
N
0
-I
..-
C
C4
0.)
C.,
ci)
0
>
ci
•-.
0.)
ci)
0)
c -[ I - - ci
0
-
0)
.
I-ci
—
Cl)
-.
a)
o
ci)
C)
C)
>
Th2
-t
C(I
.4-
10. a) Compare the atomic radii for metals and the ionic radii for their positive ions. Are the
radii for the ions or atoms larger?
cc
O( (or\c
mJLe-c
ce
-
(oie
ir,ctc
ccxcf)
*‘cir,
-c ckQ
b) Explain the above trend
(N
\J_
14.
cve
ccilic
iorS
C1c5
ks4
zc.
4
c
oc
cn
11. a) Compare the atomic radii for non-metals and the ionic radii for their negative ions. Are
the radii for the ions or atoms larger?
rncdr
\coc
b) Explain the above trend
-4he
cNS
O’XQA
c)o.4\ c-,c”r\Q
-4
ckcrs
mDc-
r,cV
cMz’\
4
cvcnS
.
1
-Ococ\
-k
\accc- mc
cJ-cr
c3
C)
12. On the periodic table below, draw arrows on the sides (going up or down and left or
right) to summarize the trends of atomic radius, ionization energy, electronegativity, and
metallic character.
÷
—
cL
-“i’
T
Do the next 3 questions using your own periodic table
listed on the provided periodic table.
—
based on the trends
—
not the values
13. Indicate which atom in each pair would have larger atomic radius.
e. Ci
f. ,eoi( )
g.
h. Fe ori)
a. Li o)
b. Ca or Ni
c. (jor B
d. 0 oI
14. Indicate which ion in each pair would have smaller ionic radius.
a.cr 02
b. (aor 1
c. i3rP
3
15. Indicate which atom or ion in each pair would have larger ionization energy.
a.Na 0
b. Be r a
c. Ar rF
d. CuorRa
16. Explain why there would be a large jump in ionization energy between the secon1 and
4c
third ionization energies for magnesium. (bc o kx*c
ce(vvenQ
cv dec.rc\r
\4\-
icLL,
C)t C
4
L’O\A
C\Q
‘o
c4
3c