1. PT LAB
Page 67 of INB

2. Procedures: Place the cards from your stack on the table.
Organize the cards the way you feel is best organizes them.
Make a chart on page 67 representing how you organized the cards. Take up the whole page.

3. Do you have all the cards?
Questions: page 66
Do you have all the cards?
What information do you think the missing cards should have?
What allowed you to predict the information from the missing card?
Sketch the missing card.

4. Organizing the elements: page 69
Essential Question: How was Mendeleev able to predict the chemical properties of the unknown elements?

5. Mendeleev: First to organize the elements.
Studied the elements and found patterns at certain intervals
1869 published the first periodic table.
Arranged by atomic mass
Started new rows when chemical properties repeated.
Left gaps for missing elements.
Some elements did not fit, so placed by chemical properties.

6. Mosley: A new arrangement, arranged by atomic number not atomic mass.
New arrangement fixed the discrepancies in Mendeleev’s table.
Periodic law: The chemical and physical properties of elements change periodically with the atomic number of the elements.

7. Periods: Across the periodic table (horizontally).
As you go from left to right
Add more protons and electrons
Become less metallic

8. Groups: Down the periodic table(Vertically) , called groups
As you go from down
All have the same chemical properties
Will react the same way
Have the same number of valence electrons.

9. Organizing Review: Page 68
Describe Mendeleev’s method for arranging the elements.
Why did Mendeleev have gaps in his table?
How is the modern table different from Mendeleev's
Are the properties of sodium more like lithium or Magnesium? Why?
Technetium was discovered in 1937, before it was discovered scientist predicted it’s properties. How were they able to do this, and what are some of it’s properties?