1. Unit 2: Atoms and Elements
Lesson 2: Periodic Table

2. Bell Work
List the Atomic theories in order and what they discovered.

3. SC Standards
7.P.2.A Conceptual Understanding: All substances are composed of one or more elements. Elements are pure substances which contain only one kind of atom. The periodic table organizes these elements based on similar properties. Compounds are substances composed of two or more elements. Chemical formulas can be used to describe compounds.
7.P.2A.2: Obtain and use information about elements (including chemical symbol, atomic number, atomic mass, and group/family) to describe the organization of the periodic table.
S.1A.8: Obtain and evaluate scientific information to (1) answer questions, (2) explain or describe phenomena, (3) develop models, (4) evaluate hypotheses, explanations, claims, or designs or (5) identify and/or fill gaps in knowledge. Communicate using the conventions and expectations of scientific writing or oral presentations by (1) evaluating grade-appropriate primary or secondary scientific literature, or (2) reporting the results of student experimental investigations.

4. Today’s Objectives (SWBAT)
Obtain and use information from secondary sources about elements to describe the organization of the periodic table.

5. Today’s Agenda
Bell Work
Review Quiz
Take Quiz
Notes on Elements

6. The Father of the Periodic Table—Dimitri Mendeleev
Mendeleev was the first scientist to notice the relationship between the elements
Arranged his periodic table by atomic mass
1869 1st Periodic Table
1871 2nd Edition Published
Protons give elements their character

7. What does the information in the box tell me?1 H
1.008
Chemical Symbol: found between the atomic number and atomic mass
Contains 1 to 2 letters of the English or Latin names
Atomic Number = # of protons
Atomic Mass = # of protons plus neutrons

8. Use of the Periodic Table
Atomic number increases from left to right
Class of elements
Metals, nonmetals, and metalloids
Properties can be predicted from the location of the element

9. The Periodic Table Column = Group or Family
18 columns on the Periodic Table
Row = Period
7 rows on the Periodic Table

10. Periods •Each row is called a “period”
•The elements in each period have the same number of energy levels
1st Period = 1 E. Level
2nd Period = 2 E. Levels
3rd Period = 3 E. Levels
4th Period = 4 E. Levels
5th Period = 5 E. Levels
6th Period = 6 E. Levels
7th Period = 7 E. Levels

11. Groups •Each column is called a “group”
•Each element in a group has the same number of electrons in their outermost energy level (valence electrons)
Group 1 = 1 electron
Except for He, it
has 2 electrons
Group 2 = 2 electrons 4
Group 8 =
8 electrons
Middle School Science Image: Chem4kids.com

12. Lesson 2: Periodic Table
Day 2

13. Bell Work Who came up with the Periodic table?
What is the difference between a period and a group?

14. Valence Electrons Have highest energy Involved in chemical bonding
Number of valence electron determines chemical properties

15. Electron Dot Diagrams
Each dot represents an electron
Each element has a specific number of valence electrons
1-8 valence electrons

16. Bonding More stable is they have 8 valence electrons
Valence electrons can be shared or transferred
Chemical bonds
Attraction that holds atoms together due to arrangement of electrons between elements

17. Metals, Nonmetals, and Semi-metals
Nonmetals are on the right of the stair-step
Only
nonmetal on the metal side
Metals are to the left of the stair- step
Semi-metals,
“metalloids,”
touch the stair-step

18. Periodic Table

19. Noble Gasses
Group 18
8 Valence Electrons
Stable-nonreactive

20. Metals Elements in the blue section
React by losing their valence electrons
Decrease from left to right
Alkali Metals
Most reactive
Explode in water

21. Nonmetals Orange section Gain or share electrons
Combine with metals by gaining electrons
React easily with other elements
7 valence electrons

22. Metalloids Lie along a zigzag line Between metals and nonmetals
Has properties of both