1. The most important tool in chemistry
Your New
♥ Best Friend ♥
The Periodic Table
The most important tool in chemistry

2. Periodic Table organization?
The periodic table will be your most useful tool; it is organized in two specific ways: 1) increasing atomic number, and 2) similar chemical properties.
family – vertical column in PT. -> elements in the same family exhibit similar chemical and physical properties 2

3. Blocks of the Periodic Table

4. Periodic Table Activity
Procedure:
1.Number the columns 1-18 across the top
2.Number the rows down the left-side
3.Fill-in 5-10 elements that you work with
4.Label the following families: alkali metal, alkaline-earth metal, transition metal, halogen, noble gas

5. Periodic Table Period – rows numbered 1 to 7.
Group – columns numbered 1 to 18; also called Families.
Group
¬Period 5

6. Periodic Table
The periodic table can be most easily be separated into three sections: Metals, non-metals, and metalloids
non-metals
Metalloids He
Metals B C N O Ne F
Noble gases Al Si P S Cl Ar Ga Ge As Se Br Kr In Sn Sb Te I Xe Tl Pb Bi Po At Rn

7. Characteristics of Metals
lustrous appearance.
mostly solids that are malleable (shapeable).
excellent electrical and thermal conductors.
tend to form (+) ions in ionic compounds→give up electrons

8. Charact. of non-Metals dull appearance.
wide diversity in physical states with solids being brittle or soft.
poor electrical and thermal conductors (great insulators!).
tend to form (-) ions in ionic compounds → gain electrons

9. Metalloids
Metalloids: Those elements with properties of metals or non-metals depending on the bond situation
(Including B, Si, Ge, As, Sb, Te)

10. Periodic Table Alkali metals – Group 1 Alkaline Earth metals – Group 2
Halogens – Group 17
Noble Gases – Group 18 10

11. Periodic Table
Transition metals – Groups 3-12
Inner Transition metals

12. Periodic Table Practice
Symbol At.# Family # Family Name Na He Li
Be 4 2 B
H 1
Alkali metal
Noble gas
Alkali metal
Alkaline earth metal
Metalloid
Family by itself

13. Diatomic Molecules Di = 2 Famous German scientist discovered:
Cl I F Br O H N 2 2 2 2 2 2 2
Molecules always want to be in pairs and NOT alone

14. Atomic Radii

15. Periodic Trends Atomic Size
The trend down a group is that atomic size increases as number of the valence shell increases

16. Periodic Trends Atomic Size
The trend across a period is that atomic size decreases because the number of protons increases but no additional energy levels are added. The more + nucleus can draw e- closer

17. Periodic Trends Ion Size
Cations are always smaller than the atom - fewer electrons so each one is held just a little bit tighter.
Cation Charge
Size
Fe(145 pm); Fe2+(74 pm); Fe3+ (64 pm)

18. Periodic Trends Ion Size
Anions are always larger than the atom - more electrons than protons in the nucleus so the charge felt per electron goes down.
Anion Charge
Size

20. Periodic Trends 1st Ionization Energy
The removal of electrons from an atom can occur two ways:
transfer to another atom.
“artificially” with external energy.
M + Energy  M+ + e-
Energy = Ionization Energy (IE)

21. Ionization Energies

22. Periodic Trends 1st Ionization Energy
Trends in IE are the reverse of atomic size trends.
smallest atomic radius highest IE
largest atomic radius lowest IE

23. Periodic Trends Electron Affinity
Electron affinity is the attraction of an atom (in the gas phase) for additional electrons.
A(g) + e-  A-(g) + Energy (exotherm)
The electron obtained always goes into the lowest energy subshell in which there is space available!

24. Electron Affinity

25. Periodic Trends Electron Affinity
smallest anion radius highest EA
largest anion radius lowest EA
Think of the electron being in a hole and the electron affinity is related to how deep the hole is!

26. Periodic Trends Electronegativity
The ability for an atom to attract electrons from a neighboring atom
smallest atomic radius has highest electronegativity- fluorine
largest atomic radius lowest electronegativity – Francium 0.7

27. Electronegativities