1. The Periodic Table and How it is Organized.

2. Why is the Periodic Table important to me?
The periodic table is the most useful tool to a chemist.
It organizes lots of information about all the known elements.

3. Pre-Periodic Table Chemistry …
…was a mess!!!
No organization of elements.
Imagine going to a grocery store with no organization!!
Difficult to find information.
Chemistry didn’t make sense.

4. Dmitri Mendeleev: Father of the Table
HOW HIS WORKED…
Put elements in rows by increasing atomic weight.
Put elements in columns by the way they reacted.
SOME PROBLEMS…
He left blank spaces for what he said were undiscovered elements. (Turned out he was right!)
He broke the pattern of increasing atomic weight to keep similar reacting elements together.

6. The Current Periodic Table
Mendeleev wasn’t too far off.
Now the elements are put in rows by increasing ATOMIC NUMBER!!
The horizontal rows are called periods and are labeled from 1 to 7.
The vertical columns are called groups and are labeled from 1 to 18.

7. Group Names
The group gets its name from the first element in the column.
The 13th column, for example, is known as the Boron group. 14th column is the Carbon group and so on.

9. Elements are arranged:
Vertically into Groups
Horizontally Into Periods

10. Why?

11. If you looked at one atom of every element in a group you would see…

12. Each atom has the same number of electrons in it’s outermost shell.
An example…

13. The group 2 atoms all have 2 electrons in their outer shells
Be (Beryllium)
Atom
Mg (Magnesium) Atom

14. The number of outer or “valence” electrons in an atom effects the way an atom bonds.
The way an atom bonds determines many properties of the element.
This is why elements within a group usually have similar properties.

15. If you looked at an atom from each element in a period
you would see…

16. Each atom has the same number of electron holding shells.
An example…

17. The period 4 atoms each have 4 electron containing shells or orbits.
4th Shell
K (Potassium)
Atom
Kr (Krypton)
Atom
Fe (Iron) Atom

18. Each group has distinct properties
The periodic Table is divided into several groups based on the properties of different atoms.
Use your blank periodic table to outline each group.
Write the title for each group.
Write the properties of each group within the outlined area of the group.

19. Alkali Metals Group 1 Soft Shiny Malleable Ductile Silvery colored
One valence electron
Very reactive with oxygen and water!!!

20. Alkali Metals reacting with water:
Li (Lithium)
Na (Sodium)
K (Potassium)
Rb (Rubidium)
Cs (Cesium)
Fr (Francium)

21. Alkaline Earth Metals Group 2
Shiny, malleable and ductile
Silvery-White Metals
Fairly reactive (combine easily with other elements)
Good Conductors of electricity
Two Valence Electrons
Many are found in rocks in the earth’s crust

22. Transition Metals Hard, Shiny, Good Conductors Fairly Stable
Groups 3-12
Hard, Shiny, Good Conductors
Fairly Stable
Often occur in nature uncombined with other elements
Malleable (easily bent/hammered into wires or sheets)

23. How many things can you think of that have Transition Metals in them?

25. Other Metals (poor metals)
Ductile (can be pulled out into wire or thread shape), Malleable, Solids,
High Density
Opaque (not transparent)
Do not oxidize as transition metals do
They share properties with both metals and non-metals
Si (Silicon) and Ge (Germanium) are very important “semi-conductors”

26. What are semiconductors used in?

27. Nonmetals Dull not shiny Not malleable Not ductile Brittle as solids
Do not conduct electricity
Some are gases at room temp.
Metals and nonmetals form compounds where electrons move from the metal to the nonmetal

28. Nonmetals What about Hydrogen??
Simplest element with one electron and one proton
Makes up 90% of the universe
Chemical properties are different from any other group
Hydrogen sits atop the periodic table as an independent

29. Halogens Most are Poisonous Seven valence electrons
Range from gases to liquids to solids at room temp.
Highly reactive especially with Alkali Metals and Alkaline Earth Metals

30. Chlorine Gas was used as a chemical weapon during World War I.
It was used by the Nazis in World War II.
Yet when mixed with sodium, harmless table salt (NaCl) is the result

31. Noble Gases Unreactive
All present in Earth’s atmosphere in small amounts
Gases at room temperature
Used in Neon lights

32. Jellyfish lamps made with noble gases artist- Eric Ehlenberger

33. Colors Noble Gases produce in lamp tubes:
Ne (Neon): orange-red
Hg (Mercury): light blue
Ar (Argon): pale lavender
He (Helium): pale peach
Kr (Krypton): pale silver
Xe (Xenon): pale, deep blue

34. Lanthanide Series Actinide Series Soft Malleable Shiny
Very good conductors
Used in industry
Usually form hard to separate compounds
Actinide Series
Only uranium and thorium are found on earth in significant amounts.
Elements after uranium are man made and very unstable