1. The

2. Historical Development of the Periodic Table
1790’s --- French scientist Antoine Lavoisier compiled a list of elements known at the time.
Many of the elements such as gold, carbon, and oxygen were known since prehistoric times.

3. Historical Development of the Periodic Table -- continued
John Newlands, an English chemist proposed an organization scheme for the known elements.
He noticed that when elements were arranged by atomic mass, their properties repeated every eighth element.
The first and the eighth elements had similar properties.

4. Historical Development of the Periodic Table -- continued
Lothen Meyer (a German chemist) & Dimitri Mendeleev ( a Russian chemist)
Organized elements by increasing atomic mass into columns with similar properties
Predicted the existence and properties of undiscovered elements.

5. The Modern Periodic Table
Groups (sometimes called Families)
Are columns numbered from 1-8, followed by a letter “A” or “B”
“REPRESENTATIVE ELEMENTS”
The groups designated with a letter “A” (1A to 8A)
“TRANSITION ELEMENTS”
The groups designated with a “B” (1B through 8B) are referred to as the
A more recent numbering system
uses the numbers 1 through 18 (also appears above each group)

6. The Modern Periodic Table --- continued
Period ( rows on the periodic table)
The periodic table consists of rows called Periods
There are a total of 7 rows or periods, beginning with hydrogen
These rows also designate the energy level where electrons are found (more about this when we talk about electron configuration).

7. The Modern Periodic Table --- Classifying the Elements
Metals
Generally shiny when smooth and clean
Solid at room temperature
Good conductors of heat and electricity
Most metals are ductile (drawn into wires) and malleable (moldable).
Metals are in green

8. The Modern Periodic Table --- Classifying the Elements
Nonmetals
Elements that are generally gases or brittle
Dull-looking solids
They are poor conductors of electricity
The only nonmetal that is a liquid at room temperature is Bromine
Non metals are in orange

9. The Modern Periodic Table --- Classifying the Elements
Metalloids
Elements with physical and chemical properties of both metals and nonmetals
Metalloids are in purple

10. THE REPRESENTATIVE ELEMENTS Group 1A – The Alkali Metals
Elements have 1 valence electron
Lose their valence electron = +1 charged ion
Good conductors of heat and electricity
Highly reactivity
Soft metals that can be cut with a knife
Silver in color
Belong to the s-block in the periodic table
Sodium- helps regulate blood pressure= modern time diets tend to contain too much salt= raised blood pressure , associated with heart problems and gives street lamps their distinctive glow

11. Alkali Metals Sodium Potassium
Gives street lamps their distinctive glow
Regulates blood pressure
Used in detergents
Submarines and space vehicles to regenerate the O2 in the air when this has become depleted
Plays key role in operation of nervous system
Sodium street lamps work by running an electrical current through an ionised gas which can then be used to vaporise the sodium. The current causes some of the electrons to collide with metal and gas ions causing the ions to absorb energy and move up to a higher energy state. When the ion reverts to its previous, lower energy level, the surplus energy is released in the form of light.

12. THE REPRESENTATIVE ELEMENTS Group 2A – The Alkaline Earth Metals
have 2 valence electrons
Lose their valence electrons = +2 charged ion
Less reactive than alkali metals
Form compounds with oxygen called oxides
Most compounds of alkaline earth metals do not dissolve easily in water
Belong to the s-block in the periodic table

13. Alkaline Earth Metals Magnesium Calcium
Used for bicycles, car and aircraft seats
Was once used in traditional flashbulbs
Builds and maintains bones and teeth

14. THE REPRESENTATIVE ELEMENTS Group 3A – The Boron Group
Named for the metalloid Boron
Elements have 3 valence electrons
Lose their valence electrons = +3 charged ion
Most often found as oxides in the earth’s crust
Boron is the only metalloid in this family, all other elements are metals
Belong to the p-block in the periodic table

15. THE REPRESENTATIVE ELEMENTS Group 4A – The Carbon Group
Is named for the nonmetal Carbon
Elements have 4 valence electrons
Lose their valence electrons to form a +4 charged ion OR can gain 4 electrons and form a –4 charged ion
Contains all three classifications: nonmetals, metalloids, and metals
Belong to the p-block in the periodic table.
Why would carbon be very important? Readiness of carbon atoms to bond with each other into chains, rings, and other frameworks enables them to provide the scaffolding of life’s molecules. Carbon is fabric of diamonds

16. THE REPRESENTATIVE ELEMENTS Group 5A – The Nitrogen Group
Is named for the nonmetal Nitrogen
Elements have 5 valence electrons
Gain 3 electrons = -3 charged ion
Except Bismuth, which can lose 3 electrons and form ions with a +3 charge
Contains all three classifications: nonmetals, metalloids, and a metal
Nitrogen essential for life, being part of DNA
Liquid N2 used as refrigerant: preservation of biological samples
Belong to the p-block in the periodic table

17. THE REPRESENTATIVE ELEMENTS Group 6A – The Oxygen Group
Is named for the nonmetal Oxygen
Elements have 6 valence electrons
Gain 2 electrons = -2 charged ion
Contains all three classifications: nonmetals, metalloids, a metal
O2 is the 3rd most abundant in the universe
No combustion without oxygenation
Belong to the p-block in the periodic table

18. THE REPRESENTATIVE ELEMENTS Group 7A – The Halogens
Are named for their ability to form compounds with all metals
These compounds are called salts therefore are also called “salt formers”
Elements in this family have 7 valence electrons
Gain 1 electron = -1 charged ion
Fluorine is a gas & the most reactive of all halogens
Chlorine is a gas at room temperature, and has disinfectant and antiseptic qualities
Iodine is a solid that can change directly into a vapor
Belong to the p-block in the periodic table

19. THE REPRESENTATIVE ELEMENTS Group 8A – The Noble Gases
Among the last naturally occurring elements to be discovered because they are colorless and unreactive
Elements in this family have 8 valence electrons
They have a full outer shell of electrons = maximum number of electrons (8 electrons) except for helium, which has two
Have no charge because they are stable
Called nobles gases because they react rarely with other elements because of their stable electron configuration
Belong to the p-block in the periodic table.
Reference to members of nobility who traditionally kept themselves aloof from other people in society

20. THE TRANSITION METALS Groups 1B- 8B (or more commonly referred to as Groups 3-12)
Are in groups 3-12 of the periodic table
Mostly dense and hard
Good conductors of electricity and heat, have luster, are malleable
Their valence electrons are in more than one electron shell
Can lose 2 electrons = +2
Can form ions with a +3 or higher
Transition metals belong to the d-block in the periodic table

21. THE INNER TRANSITION METALS -- The Lanthanide Series (Period 6 on the Periodic Table)
Elements originally found in infrequently found minerals = rare earth elements
Silvery metals with relatively high melting points
All except for promethium are nonradioactive
Compounds of lanthanides are used in movie projectors, lasers, tinted sunglasses, welder’s goggles
Belong to the f-block in the periodic table

22. THE INNER TRANSITION METALS -- The Actinide Series (Period 7 on the Periodic Table)
All are radioactive elements
Only 3 exist in nature, Thorium, Protactinium, & Uranium
The rest are synthetic elements called transuranium elements
A transuranium element is an elements whose atomic number is greater than 92
Transuranium elements are created in particle accelerators or nuclear reactors
Plutonium used as fuel in nuclear power plants
Americium is used for home smoke detectors
Belong to the f-block in the periodic table

23. NEWLY DISCOVERED ELEMENTS -- Atomic Numbers 114, 116, & 118
Some of the names of these elements are not officially assigned
Element with atomic # 114 was known as ununquadium (Uuq)
Is now know as Flerovium (Fl)
First produced by scientists in 1998 and IUPAC announced its official name until 2011
Element with atomic # 116 currently went by Ununhexium(Uuh)
Is now known as Livermorium (Lv)
First produced in 2000 and IUPAC finally recommended the new name
Element with atomic # 118 goes by Ununoctium (Uuo)
Scientists believed they had made element 118 in 2002
In 2011 IUPAC did not accept there was enough evidence to accept Uuo as an established element