1. Elements and the Periodic Table
Chapter 17

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

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

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

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

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

7. The Modern Periodic Table
Increasing Atomic Number.

8. The Modern Periodic Table
Properties were STILL grouped by column.

9. The Modern Periodic Table
So, Properties STILL repeated periodically (within a row).

10. The Modern Periodic Table
Like Cards in a deck:

11. The Modern Periodic Table
In the Modern table a PERIOD = a ROW.
How many PERIODS are there? 7

12. The Modern Periodic Table
PERIODS = ROWS
How many ELEMENTS are in PERIODS 1, 2, & 3?
What does this remind you of?

13. The Modern Periodic Table
Numbers of electrons in each ENERGY LEVEL

14. The Modern Periodic Table
In the Modern Periodic table a COLUMN = a GROUP
ELEMENTS within a GROUP have similar PROPERTIES.

15. The Modern Periodic Table
COLUMNS = GROUPS
Therefore, properties repeat PREDICTABLY and PERIODICALLY.

16. The Modern Periodic Table
THIS IS CALLED PERIODIC LAW.

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

18. The Modern Periodic Table
CLASSES OF ELEMENTS:
State: solid, liquid, gas
Natural & manmade: (91 of the first 92 are natural)
METALS, NONMETALS & METALLOIDS

19. The Modern Periodic Table
Properties????
What happens to properties when you move from left to right across the table?

20. Representative Groups
“A” GROUPS

21. GROUPS
Elements in groups have SIMILAR (not identical) PROPERTIES because they have the SAME NUMBER OF VALENCE ELECTRONS

22. Be sure to use a different color for each of the items below.
Journal
Color in the Blank Periodic Table according to the following KEY.
Be sure to use a different color for each of the items below.
METALS
NONMETALS
METALLOIDS