CS_Ch7_PeriodicTbl
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10:04 AM
Page 428
The Periodic Table
these sublevels are filled, the atom
exhibits a higher degree of stability.
In this model, the sublevels are
designated by the four letters s, p, d,
and f.
graph, not just those elements
with higher values.)
b) Which elements in the second
period (atomic numbers 3 through
10) of the periodic table have the
most stable arrangements of
electrons in their atoms?
The periodic table shows the atomic
number, the chemical symbol, and
how many electrons in an atom of
each element are in each sublevel.
The total number of electrons is
equal to the atomic number of the
element. This is because the atoms
are neutral and therefore have a
number of electrons equivalent to the
number of protons. This arrangement
of the electrons in each sublevel will
be referred to as the electron
assignment or electron configuration
of the element. Use this periodic table
to answer the following questions:
c) Which elements in the third period
(atomic numbers 11 through 18)
of the periodic table have the most
stable arrangements of electrons in
their atoms?
d) Which elements in the fourth
period (atomic numbers 19
through 36) of the periodic table
have the most stable arrangements
of electrons in their atoms?
6. As mentioned earlier, the Bohr model
was not able to account for the
spectrum of an element containing
more than one electron. A more
elaborate model was needed. In this
new model, the energy levels are
broken down into sublevels. When
GROUP
1
2
3
4
a) In what sublevel (include number
and letter) are the electrons in
hydrogen (1 electron) and helium
(2 electrons) found?
5
6
7
8
9
10
11
12
IA/1A
1
Periodic Table of the Elements
2.1
1
H
1
1.00794
1
1.0
H
Li
Be
1.00794
6.941
9.012182
Hydrogen
2
2
1s 2s
2
1
1s 2s
Atomic Number
Electronegativity
Oxidation Number
Symbol
Average Atomic Mass
Electron Configuration
Name
1
2
1
Gases at room temperature
KEY
1
1s
IIA/2A
Hydrogen Alkaline Earth
Metals
Alkali Metals
1.5
3
1.0 4
1
1s
1
Liquids at room temperature
Solids at room temperature
Metals
3
1
2
Na
Mg
22.98977
24.3050
[Ne]3s
1
[Ne]3s
2
Transition Metals
IIIB/3B
Sodium Magnesium
0.8 20
1.0 21
PERIOD
19
1
2
C
Al
Si
Ga
Ge
Nonmetals
Beryllium
Lithium
1.2
0.9 12
11
B
Metalloids
IVB/4B
1.3 22
3
VB/5B
1.5 23
3,4
1.6 24
2,3,4,5
V
VIIB/7B
1.6 25
2,3,6
VIIIB/8B
1.5 26
2,3,4,6,7
1.8 27
2,3
IB/1B
1.9 28
2,3
1.9 29
2,3
Ni
IIB/2B
1.9 30
1,2
Cu
1.6
2
K
Ca
Sc
Cr
Mn
Fe
Co
39.0983
40.078
44.95591
47.867
50.9415
51.9961
54.93805
55.847
58.93320
58.6934
63.546
65.39
[Ar]4s1
[Ar]4s2
[Ar]4s23d1
[Ar]4s23d2
[Ar]4s23d3
[Ar]4s23d4
[Ar]4s23d5
[Ar]4s23d6
[Ar]4s23d7
[Ar]4s23d8
[Ar]4s23d9
[Ar]4s23d10
Potassium
Calcium
Scandium
Titanium
Vanadium Chromium Manganese
Iron
Cobalt
Nickel
Copper
Zinc
Rb
Sr
Y
Zr
Nb 428Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Cs
Ba
*La
Hf
Ta
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
4
Ti
VIB/6B
Zn
Active Chemistry
W
CS_Ch7_PeriodicTbl
2/28/05
10:04 AM
Page 429
Activity 6 Atoms with More than One Electron
As you move to the second period
(second row on the periodic table)
each new element has one more
proton in its nucleus and one more
electron. The electrons must find a
place to reside — an energy level and
a sublevel within that energy level.
As you move along in the periodic
table to increasing atomic
numbers, you see that the
additional electrons fill the
sublevel. A completed sublevel is
one that is holding the maximum
number of electrons allowed to it
before electrons must be placed in
the next higher sublevel.
b) In what region of the periodic
table are electrons added in an
s sublevel? What is the greatest
number of electrons found in any
s sublevel?
c) In what region of the periodic
table are electrons added in a
p sublevel? What is the greatest
13
14
15
16
17
18
VIIIA/8A or 0
Noble Gases
2
He
4.002602
IIIA/3A
5
2.0
3
B
2
6
2.5
-4,2,4
1
1s 2s 2p
2
7
3.0
N
12.011
2
VA/5A
VIA/6A
VIIA/7A
1s
Chalcogens
Halides
Helium
8
3.5
-3,2,3,4,5
C
10.811
2
IVA/4A
2
1s 2s 2p
2
4.0 10
-2
-1
O
14.00674
2
9
3
1s 2s 2p
F
15.9994
2
2
2
4
1s 2s 2p
Ne
18.998403
2
2
5
1s 2s 2p
20.1797
2
2
6
1s 2s 2p
Boron
Carbon
Nitrogen
Oxygen
Fluorine
Neon
13
1.5 14
1.8 15
2.1 16
2.5 17
3.0 18
3
2,4
-3,3,4,5
-2,2,4,6
Al
Si
P
S
-1,1,3,5,7
26.981539
28.0855
30.973762
32.066
35.4527
39.948
[Ne]3s23p1
[Ne]3s23p2
[Ne]3s23p3
[Ne]3s23p4
[Ne]3s23p5
[Ne]3s23p6
Cl
Ar
number of electrons found in any
p sublevel?
d) In what region of the periodic
table are electrons added in a
d sublevel? What is the greatest
number of electrons found in
any d sublevel?
e) In what region of the periodic
table are electrons added to an
f sublevel? What is the greatest
number of electrons found in any
f sublevel?
f) Select a column in the periodic
table. (A column of elements on
the periodic table is called a family
or group.) Look at the electron
configuration for each element
within the column. Take special
note of the last entry, the sublevel
to which the last electron in an
atom of each element in that
column is added. What do all of
these sublevels have in common?
How many electrons are in these
particular sublevels?
g) Mendeleev assigned elements to
the same column of the periodic
table because the elements had
similar properties, both physical
and chemical. How, then, does
the number and location of the
electrons in the outermost
sublevel relate to chemical
properties? We can now
acknowledge that electrons (as
opposed to the nucleus) are the
key to the chemical properties
of elements.
Aluminum
Silicon Phosphorus Sulfur
Chlorine
Argon
1.6 32
1.8 33
2.0 34
2.4 35
2.8 36
31
Cu
Zn
3
4
-3,3,5
-2,4,6
Ga
Ge
As
Se
-1,1,5,7
Br
Kr
69.723
72.61
74.92159
78.96
79.904
83.80
[Ar]4s23d104p1 [Ar]4s23d104p2 [Ar]4s23d104p3 [Ar]4s23d104p4 [Ar]4s23d104p5 [Ar]4s23d104p6
Ag
Cd
Gallium
Germanium
Arsenic
Selenium
Bromine
Krypton
In
Sn
Sb
Te
I
Xe
429
Coordinated Science for the 21st Century
Au
Hg
Tl
Pb
Bi
Po
At
Rn