1. Unit Seven: Periodic Table

2. Background to the Periodic Table:
Elements are arranged on the periodic table according to similar properties.
The modern periodic table is organized by increasing atomic number.

3. Background to the Periodic Table:
Ted ed: Periodic Table
Dimitri Mendeleev , a Russian scientist, is credits for creating the first periodic table in 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.
Henry Mosely later rearranged the periodic table based on increasing atomic number. This arrangement is still used today.
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.

4. Period
Group or Family
Group or family
Period

5. Classification of Elements
Elements on the periodic table can be classified in one of the three following groups:
Metals
Nonmetals
Metalloids
Metals are located on the left side of the periodic table
Non metals are located on the right side of the periodic table.
The six metalloids fall along the “steps”. They include:
Boron (B), Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb), Tellurium (Te)

6. Classification of the Periodic Table:

7. 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

8. 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

9. 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

10. Examples of Nonmetals
Microspheres of phosphorus, P, a reactive nonmetal
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

11. 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

12. 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

13. Periodic Table: Metallic arrangement
Layout of the Periodic Table: Metals vs. nonmetals
Nonmetals
Metals

14. Reading the Periodic Table: Classification
Nonmetals, Metals, Metalloids, Noble gases

15. 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.

16. Down the Periodic Table
Family: Are arranged vertically down the periodic table (columns or group, )
These elements have the same number electrons in the outer most shells, the valence shell.
Alkali Family:
1 e- in the valence shell
Halogen Family:
7 e- in the valence shell

17. Groups/Families and Chemical Properties:
Table of element families & properties:
Group #1 Alkali Metals Reactive, soft metals,
1 valence electron
Group #2 Alkaline Earth Metals 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

18. Infamous Families of the Periodic Table
Notable families of the Periodic Table and some important members:
Alkali
Alkaline (earth)
Transition Metals
Noble Gas
Halogen
Chalcogens