1. Elements and the Periodic Table
Chapter 5

2. 5.1 - Journal Take out your homework
Color in the Periodic Table given to you and color it in according to the following LIST. Use your book, too!
Use a different color for each of the items below.
Alkali Metals
Alkaline Earth Metals
Transition Metals
Metalloids
Nonmetals
Halogens
Noble Gases
Other metals

3. 5.1 – Journal
Check your Periodic Table

4. 5.1 - Organizing the Elements
MENDELEEV’S ORDER
Dmitri Mendeleev
Trying to organize the 63 known elements so they were easier to understand

5. 5.1 - Organizing the Elements
MENDELEEV’S ORDER: Didn’t yet know about protons, neutrons and electrons, ONLY MASS.. What could he do?

6. 5.1 - Organizing the Elements
MENDELEEV’S ORDER: Increasing Atomic Mass
Elements with similar properties were put in the same column

7. 5.1 - Organizing the Elements
Named “Periodic Table” because properties repeated ‘periodically’ from row to row.
Like keys on a keyboard (octaves)

8. 5.2 – The Modern Periodic Table
The Periodic Law
Once protons were discovered, what were elements organized by?

9. Increasing Atomic Number.

10. Properties ARE STILL grouped by column.

11. So, Properties STILL repeat periodically (within a row).

12. 5.2 – The Modern Periodic Table
Like Cards in a deck:

13. In the Modern table a PERIOD = a ROW. How many PERIODS are there? 7

14. Numbers of electrons in each ENERGY LEVEL
PERIODS = ROWS
How many ELEMENTS are in PERIODS 1, 2, and 3?
What does this remind you of?
Numbers of electrons in each ENERGY LEVEL

15. ELEMENTS within a GROUP have similar PROPERTIES.
a COLUMN = a GROUP
ELEMENTS within a GROUP have similar PROPERTIES.

16. Therefore, properties repeat PREDICTABLY and PERIODICALLY.
COLUMNS = GROUPS
Therefore, properties repeat PREDICTABLY and PERIODICALLY.
THIS IS CALLED PERIODIC LAW.

17. 5.2 – The Modern Periodic Table
Example
Group (Family 1) – Alkali Metals
What is similar?

18. 5.2 – The Modern Periodic Table
There are 4 important pieces of information for each element
Atomic number
Element symbol
Element name
Atomic mass

19. 5.2 – The Modern Periodic Table - Journal
What happens to properties when you move from left to right across the table?
What type of elements are in yellow? In green? In blue?
What is the definition of a “metalloid”?
What type of elements are in the “B” columns?
List the names of all of the “A” groups (families).
What is an important fact about the Actinide series?

20. 5.2 – The Modern Periodic Table
HOW CAN WE CLASSIFY ELEMENTS?
State: solid, liquid, gas
Natural & manmade: (91 of the first 92 are natural)
METALS, NONMETALS & METALLOIDS

21. 5.2 – The Modern Periodic Table
Classified by Properties
What happens to properties when you move from left to right across the table?

22. 5.3 – Representative Groups
Elements in a group have SIMILAR (not identical) PROPERTIES because they have the same number of valence electrons

23. 5.3 – Representative Groups
ALKALI METALS (group 1):
Single valence electron
EXTREMELY REACTIVE
Reactivity increases from
top to bottom
It is not a metal, but Hydrogen is
grouped here. Why?

24. 5.3 – Representative Groups
ALKALINE EARTH METALS (group 2):
TWO valence electrons
Less reactive than group 1

25. 5.3 – Representative Groups
BORON FAMILY (group 3A):
THREE valence electrons
FYI- Aluminum is the most
abundant metal in Earth’s crust

26. 5.3 – Representative Groups
CARBON FAMILY (group 4A):
FOUR valence electrons
FYI- Except for water, most compounds in your body contain Carbon.

27. 5.3 – Representative Groups
NITROGEN FAMILY (group 5A):
FIVE valence electrons
FYI- Nitrogen and Phosphorous are used to make fertilizers.

28. 5.3 – Representative Groups
OXYGEN FAMILY (group 6A):
SIX valence electrons
FYI- Oxygen is the most abundant nonmetal in Earth’s crust, and Ozone is another form of oxygen.

29. 5.3 – Representative Groups
THE HALOGENS (group 7A):
SEVEN valence electrons
EXTREMELY REACTIVE
Reactivity increases from bottom to top
FYI- Halogen means “salt former”.

30. 5.3 – Representative Groups
THE NOBLE GASES (group 8A):
EIGHT valence electrons
INERT (don’t react easily)
FYI- make “neon” lights when a current is passed thru them.