1. DISCOVERING THE PERIODIC LAW
IT’S IN THE CARDS
DISCOVERING THE PERIODIC LAW

2. “I wish to establish some sort of system of elements in which their distribution is not guided by chance…but by some sort of definite and exact principle.” -Dmitri Mendeleev’s

3. Dmitri Mendeleev’s discovery of the Periodic Law is one of the greatest achievements in science
Let’s go back in time and experience how this was achieved…
What did Mendeleev know and when did he know it?
INTRODUCTION

4. Mendeleev knew the atomic masses, densities, boiling points, melting points, formulas of hydrogen, oxygen and chlorine compounds and other isolated facts
Wanted a way to organize these facts…
Wrote out separate cards for each element, with their properties and played a chemical solitaire until the elements were arranged.
BACKGROUND

5. To re-create Mendeleev’s discovery of the classification of elements and the periodic law using a special deck of element cards.
PURPOSE

6. TASK FOR TODAY-OCTOBER 19, 2016
GOAL: DO A BIT OF RESEARCH AND SET UP NOTEBOOK FOR NEXT LAB (INQUIRY BASED) ON THE DEVELOPMENT OF THE PERIODIC TABLE
READ THE BACKGROUND & PURPOSE OF THE LAB. RECORD A BRIEF SUMMARY OF BOTH IN YOUR LAB NOTEBOOK UNDER A “BACKGROUND SECTION” AND A “PURPOSE SECTION”
WORK ON DEFININING THE TERMS FOR THE PRE-LAB QUESTIONS. USE YOUR TEXTBOOK AND THE INTERNET

7. The element cards list all of the following properties for each element. Use your textbook to write a clear definition of each property. Give the typical units for each numerical property, if appropriate.
Ionization Energy
Atomic radius
Melting point
Atomic mass
Density
Electronegativity
PRE-LAB QUESTIONS

8. LAB NOTEBOOK DATE TITLE PURPOSE PRE-LAB QUESTIONS MATERIALS PROCEDURE
DATA SHEET
LAB NOTEBOOK

9. PROCEDURE Get into groups of 3—4 Cut the cards from paper.
Follow the procedure in your Lab Report
Make sure you work in a collaborative manner to discuss the possibilities for arrangement.
PROCEDURE

11. TODAY ACCURATELY FOLLOW THE PROCEDURE
One of the elements from your desk is labeled “MISSING”…decide where that missing element will go based on your arrangement
ORGANIZE ELEMENTS AND WRITE ON 8X8
Make note of each element in the arrangement by placing its atomic mass number
TODAY

12. PLACING YOUR ARRANGEMENT
6.9
16.0 …
9.0
19.0
10.8
20.2
12.0
23.0
14.0
24.3
27.0
28.1
PLACING YOUR ARRANGEMENT

13. POST-LAB QUESTIONS Answer questions 1-9
Retrieve Handout on Possible Arrangement for Questions 4 & 5
POST-LAB QUESTIONS

14. HONORS CHEMISTRY INFO TO DISCUSS OCTOBER 21, 2016
PREPARATION FOR THE WEEKEND: POST LAB QUESTIONS 6—9
TAKE A PICTURE OF HANDOUT OF A POSSIBLE ARRANGEMENT
TAKE A PICTURE OF YOUR ARRANGMENT
TESTS & RETAKES
SCIENCE NIGHT VOLUNTEERS

15. HONORS CHEMISTRY TASK LIST—OCTOBER 21, 2016
Make sure you answered Pre-Lab Question #1 (Definitions & Units)
Finish organizing your elements and placing them on the construction paper to make YOUR groups Periodic Table
Predict the properties of your “Missing Element” by placing it on your Periodic Table where you think it fits based on trend. This prediction is a round about average…does not have to be exact, but has to make sense.
Start answering the Post-Lab Questions. Use Textbook and Modern Day Periodic Table

16. THE LAB REPORT –It’s In The Cards
So…What Am I Grading To Assess?
Here’s Your Checklist
Notebook Completed (Title, Purpose, Background, etc…)
Data Table (with YOUR Periodic Table order AND predicted properties of “Missing Element”)
Post-Lab questions 1-9—completed, with just the answers and the tables they ask you to construct.

18. A Periodic Trend

19. POST LAB QUESTIONS HELP
QUESTION 1 Use our discussion about the definition of “periodic,” and its relationship to trends in properties of the elements, to help answer this question. Also know that periodic does NOT mean linear!
POST LAB QUESTIONS HELP

20. POST LAB QUESTIONS HELP
QUESTION 2 To maneuver through this question, you might want to use the “Element Card Arrangement Handout” OR the real Periodic Table to look at the values of your properties and note which ones are periodic (increase or decrease in intervals) and which are just linear (increase altogether or decrease altogether). To help…Atomic Mass is a property that is NOT periodic…it is linear. It increases continually!
POST LAB QUESTIONS HELP

21. POST LAB QUESTIONS HELP
QUESTION 3 Think about atomic history that we discussed with the “Investigations into the Atom” activity and the timeline. Also think about the year in which Mendeleev organized the periodic table. What kind of atomic model was present at this time?
POST LAB QUESTIONS HELP

22. POST LAB QUESTIONS HELP
QUESTION 4 For this question, you will want to use a REAL Periodic Table to identify the elements in the “Handout.” The way Mendeleev identified elements was by their atomic mass (which is inaccurate today!) For example, the first element in the table on the handout has an atomic mass of 6.9. If you search the Periodic Table, you will see that the only element with that mass is Lithium, Li. Lithium has an atomic number of 3.
POST LAB QUESTIONS HELP

23. POST LAB QUESTIONS HELP
After figuring out the atomic numbers of your elements, you should know the following numerical properties are periodic:
Electronegativity
Ionization energy
Atomic Radius
If you plot these properties with respect to atomic number, you will achieve creating a periodic trend on the graphs
POST LAB QUESTIONS HELP

24. POST LAB QUESTIONS HELP
Look at a REAL Periodic Table, and look at the first 18 elements with the following properties and their numerical values (given on the element cards.
Electronegativity
Ionization energy
Atomic Radius
Think about whether or not each property increases/decrease from left to right (across a Row) or increases/decreases from top to bottom (Down a Group) That is how you will label that Periodic Table.
POST LAB QUESTIONS HELP

25. POST LAB QUESTIONS HELP
QUESTIONS 7, 8, AND 9
You can look up in your textbook, or online, where the following types of elements are:
Metals, Nonmetals, Metalloids
Metals are all the to the left of the metalloids
Metalloids are Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium, and Astatine
Nonmetals are all to the right of the metalloids. (Except Hydrogen)
Alkali & Alkaline Metals
Group 1A = Alkali Metals Group 2A = Alkaline Metals
Halogens = Group 7
Noble Gases = Group *
Groups(Families)-Vertical Columns in the Periodic Table
Periods (Series)-Horizontal Rows in the Periodic Table
POST LAB QUESTIONS HELP

26. POST LAB QUESTIONS HELP
QUESTIONS 7, 8, AND 9
POST LAB QUESTIONS HELP