Download Unit Six: Atomic structure

Unit Seven: Periodic Table
Background to the Periodic Table:
1. Elements are arranged on the periodic table according to similar properties.
2. The modern periodic table is organized by increasing atomic number.
Background to the Periodic Table:
Ted ed: Periodic Table
1. Dimitri Mendeleev , a Russian scientist, is credits for creating the first periodic table in 1869. At that
time, there were only 60 known element and Mendeleev organized them according to their atomic mass.
Mendeleev was able to predict the properties of missing elements which were later discovered. These
elements fit perfectly in the missing gaps.
2. Henry Mosely later rearranged the periodic table based on increasing atomic number. This arrangement
is still used today.
3. The columns on the periodic table are called groups, the rows are called periods.
There are 18 groups (columns) and 7 periods (rows) on the periodic table.
Period
Group or Family
Group or
family
Period
Classification of Elements
• Elements on the periodic table can be classified in one of the three
following groups:
• Metals
• Nonmetals
• Metalloids
a. Metals are located on the left side of the periodic table
b. Non metals are located on the right side of the periodic table.
c. The six metalloids fall along the “steps”. They include:
Boron (B), Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb), Tellurium (Te)
Classification of the Periodic Table:
Properties of Metals
 Metals are good conductors of heat and
electricity
 Metals are malleable
 Metals are ductile
 Metals have high tensile strength
 Metals have luster
Examples of Metals
Potassium, K reacts
with water and must
be stored in
kerosene
Copper, Cu, is a relatively soft metal, and a very good
electrical conductor.
Zinc, Zn, is more stable
than potassium
Mercury, Hg, is the only metal that exists as
a liquid at room temperature
Properties of Nonmetals
Carbon, the graphite in “pencil lead” is a great example of a nonmetallic
element.
 Nonmetals are poor conductors of heat and
electricity
 Nonmetals tend to be brittle
 Many nonmetals are gases at room temperature
Examples of Nonmetals
Sulfur, S, was once known
as “brimstone”
Graphite is not the only pure form of
carbon, C. Diamond is also carbon; the
color comes from impurities caught within
the crystal structure
Microspheres of
phosphorus, P, a
reactive nonmetal
Properties of Metalloids
Metalloids straddle the border
between metals and nonmetals on the
periodic table.
 They have properties of both metals and nonmetals.
Metalloids are more brittle than metals, less brittle than most nonmetallic
solids
 Metalloids are semiconductors of electricity
 Some metalloids possess metallic luster
Silicon, Si – A Metalloid
 Silicon has metallic luster
 Silicon is brittle like a nonmetal
 Silicon is a semiconductor of electricity
Other metalloids include:
 Boron, B
 Germanium, Ge
 Arsenic, As
 Antimony, Sb
 Tellurium, Te
Periodic Table: Metallic arrangement
• Layout of the Periodic Table: Metals vs. nonmetals
1
IA
1
18
VIIIA
2
IIA
13
IIIA
14
IVA
15
VA
16
VIA
17
VIIA
2
3
4
5
6
7
3
IIIB
4
IVB
5
VB
6
VIB
7
VIIB
8
9
VIIIB
Metals
10
11
IB
12
IIB
Nonmetals
Reading the Periodic Table: Classification
• Nonmetals, Metals, Metalloids, Noble gases
Groups/Families and Chemical Properties:
The vertical columns on the periodic table are called groups.
There are 18 groups on the periodic table.
Elements in a group have the same valence electrons and
because of this, they have similar chemical properties.
Down the Periodic Table
•Family: Are arranged vertically down the periodic table (columns or group, 1- 18 )
•These elements have the same number electrons in the outer most shells, the valence shell.
1
IA
1
18
VIIIA
Alkali Family:
1 e- in the valence shell
2
IIA
13
IIIA
14
IVA
15
VA
16
VIA
2
3
3
IIIB
4
IVB
5
VB
6
VIB
7
VIIB
8
9
VIIIB
10
11
IB
12
IIB
4
5
6
7
Halogen Family:
7 e- in the valence shell
17
VIIA
Groups/Families and Chemical Properties:
Table of element families & properties:
Group #1
Group #2
Alkali Metals
Alkaline Earth Metals
Reactive, soft metals,
1 valence electron
Reactive metals, harder than alkali metals,
2 valence electrons
Group #17
Halogens
Reactive non-metals
7 valence electrons
Group #18
Noble Gas
Unreactive non-metals, all are gases
8 valence electrons
Infamous Families of the Periodic Table
• Notable families of the Periodic Table and some important members:
Halogen
Noble Gas
Chalcogens
Alkali
Alkaline
(earth)
1
IA
1
18
VIIIA
2
IIA
13
IIIA
Transition Metals
2
3
4
5
6
7
3
IIIB
4
IVB
5
VB
6
VIB
7
VIIB
8
9
VIIIB
10
11
IB
12
IIB
14
IVA
15
VA
16
VIA
17
VIIA