1. Unit 4: Periodic Table & Periodic Trends
EQ: How does the organization of the periodic table allow us to make predictions or determine the behavior & properties of elements?

2. GPS
SC4. Students will use the organization of the Periodic Table to predict properties of elements.
a. Use the Periodic Table to predict periodic trends including atomic radii, ionic radii,
ionization energy, and electronegativity of various elements.
b. Compare and contrast trends in the chemical and physical properties of elements and
their placement on the Periodic Table.

3. Key Vocabulary Terms Law of Octaves Periodic Table Periodic Law
Periods
Group/ Family
Valence Electron
Periodic Trends
Atomic Radius
Ionic Radius
Ionization Energy
Electronegativity
Electron Affinity

4. The History Dobereiner Found elements could be put in Triads Newlands
Discovered the Octet Rule when classifying elements
Mendeleev
First to organize elements by increasing mass to create the Periodic Table

5. J. W. Dobereiner ( )
Observed that several elements could be classified into sets of three a.k.a. Triads
His Triads included….
Lithium, Sodium, and Potassium
Calcium, Strontium, and Barium
Chlorine, Bromine, and Iodine

6. Triads Grouped By Similar Chemical Properties
Many Properties of Middle Elements Are Approximate Averages Of The Properties Of The 1st And 3rd Element

7. EXAMPLE ELEMENT ATOMIC MASS Density Cl 39.5 1.56 Br 79.9 3.12 L 126.9
4.95

8. J.A.R. Newlands ( )
Presented the idea that when the elements were arranged in order of increasing atomic mass, the properties of every eighth element was like that of the first in the set:1st-8th, 2nd-9th, and so on
Called the pattern the law of octaves

9. Dmitri Mendeleev (1834-1907) Lothar Myer (1830-1895)
Published nearly identical schemes for classifying the elements
Mendeleev is given more credit since he published first and was more successful at demonstrating it
Mendeleev also put breaks in the Table where other elements were yet to be found b/c he knew they had to fit in to make the table work right

10. Mendeleev
Noticed that when he arranged the elements by increasing atomic mass he could see a periodic repetition of their properties
Used this to create the first Periodic Table
Wanted to make the elements easier to learn and understand

11. Moseley Moseley Developed atomic number concept for the atom
Arranged elements by increasing atomic number rather than mass as Mendeleev had

12. The Periodic Law
when elements are arranged in order of increasing atomic number, their physical and chemical properties show a periodic pattern

13. A. Periodic Law
When elements are arranged in order of increasing atomic #, elements with similar properties appear at regular intervals.

14. Reading the Table
Groups/Families are elements with similar properties and run up and down. There are 18 families.
Periods run left to right on the table. There are 7 periods.
Groups to remember
(1)- Alkali Metals
(2)- Alkaline-earth Metals
(3-12)- Transition Metals; d-block
Inner transition Metals (bottom); f-block
(17)-Halogens
(18)- Nobel Gases

15. Reading the Table (Cont.)
Metals
Have luster (a shine)
Good conductors (of heat & electricity)
Solids usually
Malleable (can be pounded into sheets)
Ductile (pulled into a wire)
Nonmetals
No luster
Poor conductors
Many are Gases
Big variation in physical properties
Metalloids/ semi-metals
--Have properties of metals and nonmetals
-form the steps; except Al.

16. Electrons and The Table
Electrons fill atoms in s-, p-, d- and f- orbitals. These orbitals have a location on the P.T.
S-block: left side.
P-block: right side.
D-block: Transition Metals.
F-block: Inner Transition Metals.

17. Classification of the Elements
The periodic table is divided into blocks that correspond to the sub-levels that are being filled with electrons
S block: Group 1& 2
P block: Groups (except for Helium)
D block: transition metals
F block: inner transition metals

18. Classification of the Elements
The periodic table is one of the most important tools in chemistry
Elements are arranged according to atomic number, but the periodic table also relates to atomic structure and trends among the elements
Elements can be classified into 4 categories according to their electron configurations

19. Classification of the Elements
The noble gases
Elements in which the outermost s and p sublevels are filled
Also known as inert gases
The representative elements
Elements in which the outermost s or p sublevel is only partially filled
Usually called the Group A elements
Group 1 elements are the alkali metals
Group 2 elements are the alkaline earth metals

20. Important Group names Alkali Metals Alkaline Earth Metals
Transition Metals
Halogens
Noble Gases

21. Classification of the Elements
The transition metals
Metallic elements in which the outermost s sublevel and nearby d sublevel contain electrons
Called the Group B elements
Characterized by the addition of electrons to the d orbitals
The inner transition metals
Metallic elements in which the outermost s sublevel and the nearby f sublevel generally contain electrons
Characterized by the filling of f orbitals