1. History of the Periodic Table

2. Vocabulary Metal Shiny Non-Metal Ductile Period Malleable Properties
Transition Elements
Noble Gases
Halogens
Alkali Metals
Alkaline Earth Metals
Shiny
Ductile
Malleable
Metalloids

3. Antoine Lavoisier
In the late 1790s, he compiled a list of the known elements at the time.
This list contained 23 elements.

4. But times were about to change…
In the 1800’s, there were many changes in the world
Electricity
Spectrometer
Industrial Revolution
As a result, there was an increase in the number of known elements
By the 1870, there were 70 known elements

5. An agreement is reached…
Then in the 1860’s, chemist agreed upon a method for accurately determining the atomic mass of elements.

6. John Newlands
Noticed when elements were arranged by atomic mass, they repeated properties every 8th element.
He used the word periodic to describe this pattern
He gave it the name the Law of Octaves

7. Unfortunately… Did not work for all the elements
Criticized because of its association with music
Did give others the idea of repeating properties - periodic
We Hate It

8. Lothar Meyer and Dmitri Mendeleev
Each made a connection between atomic mass and properties of elements

9. The winner is… Mendeleev
Mendeleev is given credit because his was published first
In addition, Mendeleev predicted unknown elements
However, not completely correct – new elements weren’t in correct order

10. Henry Moseley
Solved this problem by arranging the elements by increasing atomic number.
The periodic repetition of chemical and physical properties of elements when arranged by atomic number is now known as Periodic Law

11. Which leads to the Modern Periodic Table
Boxes each with:
Hydrogen
Element Name 1
Atomic Symbol
Atomic Number H
Atomic Mass
That are arranged by increasing atomic numbers

12. Remember
Atomic number = the number of protons = the number of electrons (if neutral atom)
Atomic Mass on the Periodic table is the average mass of the isotopes
But the mass number of each isotope is the protons plus the neutrons

13. Chemical Symbol The symbol that refers to the element
First letter is capitalized, second letter (if applicable) is lower case
Not all symbols are based on English names for the elements, some come from their Latin names or even other languages
– Tin – Sn – stannum
– Iron – Fe - ferrum
– Mercury – Hg - hydrargyrum
– Gold – Au - aurum
– Silver – Ag – argentum
– Antimony – Sb -stibium
– Lead – Pb – plumbum
– Copper – Cu – cyprium

14. Columns and Rows The columns are called Families or Groups
Earlier Version had 1-8 followed by A or B
Group A elements are called Representative Elements
Group B elements are called Transition Elements
Modern Version labels the columns with 1-18
Rows are called Periods
Seven periods for the seven energy levels (rings)

15. Classifying Elements Three Types of Elements Metals Nonmetals
Metalloids

16. Metals Shiny when smooth and clean Solid at room temperature
Only exception - Mercury
Good conductors of heat and electricity
Most are ductile and malleable

17. Most of the elements on the table are metals, which are in blue

18. Nonmetals Upper Right side of the Periodic Table
Generally brittle solids or gases
Poor conductors of heat and electricity
Bromine is the only liquid at room temperature

19. “The Yellow Elements”

20. Metalloids A.k.a – the semi-metals Boxes bordering the stair-step
Physical and chemical characteristics of both metals and nonmetals

21. “The Green Stair-stepping Elements”