3. Friday, Nov. 22 nd : “A” Day Monday, Nov. 25 th : “B” Day Agenda  Collect Popcorn Lab/Chapter3 Tests: “Atoms & Moles”  Movie: “Electron Configuration and the Periodic Table”  Begin Chapter 4: The Periodic Table Sec. 4.1: “How Are Elements Organized?”  In-Class/Homework: Section 4.1 review, pg. 122: #1-13 “What is the Periodic Table?” Worksheet Finish movie worksheet  Homework: Concept Review: “How Are Elements Organized?”

4. Popcorn Lab Reflection Statement 1.Was your hypothesis correct? 2.What were some possible sources of error in this lab? 3.How could you minimize these errors in future trials? 4.Did this lab help you understand how the law of conservation of mass could be used?

5. Chapter 3 Tests “Atoms and Moles” ClassAverage Grade (out of 70) Average Percentage 2A53.8376.90% 4A58.6883.83% 1B62.4489.20% 3B64.6592.36%

6. Movie: “Electron Configuration and the Periodic Table”  Complete the blank periodic table worksheet along with Mr. Sweatervest as he discusses electron configurations and the periodic table.  The completed periodic table worksheet will be due next time.  Extra credit: keep track of how many times Mr. Sweatervest thinks electron configurations are “interesting”.

7. Chapter 4: The Periodic Table  Patterns in Element Properties  The Periodic Law This guy is almost as handsome as Mr. Sweatervest!

8. John Newlands Noticed a Periodic Pattern  In 1865, English chemist John Newlands arranged the known elements according to their properties and in order of increasing atomic mass.  Newlands noticed that all of the elements in a given row had similar chemical and physical properties and these properties repeated every 8 elements.  Newlands called this pattern the law of octaves.

9. Dmitri Mendeleev Invented the First Periodic Table  In 1869, Russian chemist Dmitri Mendeleev made the first periodic table with all of the 63 elements known at that time.  He wrote the chemical symbol, name, chemical/physical properties, and atomic mass on cards.  He arranged the cards in order of increasing atomic mass.

10. Dmitri Mendeleev Invented the First Periodic Table  Mendeleev started a new row whenever he noticed the chemical properties of the elements were repeating.  He left gaps in his table for elements that weren’t discovered yet.  Problem: The elements didn’t always fit neatly in order of increasing atomic mass. (Examples: Te and I)

11. Henry Moseley  About 40 years after Mendeleev’s published periodic table, English chemist Henry Moseley found a different physical basis for the arrangement of elements.  He arranged them by increasing atomic number and the discrepancies in Mendeleev’s table disappeared.

12. The Periodic Law Periodic Law: the law that states that the repeating physical and chemical properties of elements change periodically with their atomic number.

13. Organization of the Periodic Table  If you look at the blank periodic table you filled out while watching the last Mr. Sweatervest video, you’ll see that each vertical column of elements in the periodic table have the same number of electrons in their outer energy level.  These electrons are called valence electrons.  Valence electron: an electron found in the outermost level of an atom that determines the atom’s chemical properties.

14. Organization of the Periodic Table  Group/Family: a vertical column of elements in the periodic table; elements in a group share similar chemical properties.  Period: a horizontal row of elements in the periodic table; elements in a period have the same number of occupied energy levels. G R O U P P E R I O D

15. In-Class/Homework  Section 4.1 Review, pg. 122: #1-13  “What is the Periodic Table?” Worksheet  Finish movie worksheet  Homework: Concept Review: “How are Elements Organized?” *Quiz over section 4.1 next time*