1. The Evolution of Atomic Theory
Chapter 3
The Evolution of Atomic Theory

2. Chapter 3 Essential Questions
What is atomic theory?
What is an atom?
What is an isotope & atomic mass?
What are electrons?
What are orbitals & configurations?
What is light & electromagentism?

3. Question of the Day Famous Daltons: Dalton from the movie Roadhouse
Timothy Dalton 007
Darren Dalton Phillies Catcher
Who is the most famous Dalton?

4. Dalton’s Atomic Theory
Early 1800s
English school teacher
Used Scientific Method to find out atomic theory
1st Law - matter isn’t created or destroyed (conservation of matter)
2nd Law - many samples of same chemical contain identical % (constant composition)

5. Rehashing Dalton More Theory of Dalton All matter is made of atoms
Cant be created or destroyed
2 of the atoms are the same (size, mass & property)
2 different elements are different
Chem Rxns unite or separate atoms

6. The Atom Nucleus - center of an atom where protons & neutrons are
Proton - positive charged ion in nucleus
Neutron - uncharged ion in nucleus
Electron - negative charged ion in motion around nucleus

7. Elements & Isotopes Elements - Pure Substance (ex. Hydrogen, Carbon)
Mass Number - # of protons & neutrons
Atomic Number - # of protons
Isotopes - molecules with diff. # of neutrons
Hydrogen, Deuterium & Tritium

8. The Periodic Table (Elements)

9. Law of Mendeleev 1st guy to list all elements on a table
Original had 70 elements
Today we have 113
Mendeleev arranged them by trends

10. Periodic Groups
Arranged by vertical columns (8 Groups) w/ similar properties
Group 1 Alkali Metals (Red)
Group 2 Alkaline Earth Metals (Purple & Blue)
Group 3 (Green)
Group 4 (Olive)
Group 5 (Beige)
Group 6 Chalcogens (Orange)
Group 7 Halogens (Brown)
Group 8 Noble Gases (Yellow)

11. Rows or Periods Also arranged by horizontal rows (7 periods)
Hydrogen & Helium are separate
Based on relative size
Period 6 & 7 include Actinides & Lanthanides

12. Alkali Metals & Alkaline Earth Metals
1st Column (Group I)
Alkali - react with H2O to form a basic solution
Hydrogen not a metal but still is part of group (gas at room temp)
All elements have a +1 ion charge
H, Li, Na, K
2nd column (GroupII)
Alkaline Earth Metals - also react with H20 to form bases
All elements have +2 ion charge
Be, Mg, Ca, Ba
*Both groups are metals and good conductors of electricity

13. Groups 3, 4 & 5 Begins with nonmetals
Boron is only nonmetal in Group III
Begins also with metalloids - 1/2 metal & 1/2 nonmetal
Metalloids - B, Si, Ge, As, Sb, Te, Po
Important Group III elements B, Al
All have +3 ion charge
Group IV has some nonmetals, C & Si
1 important metal Sn
+4 or -4 ion charge - good at bonding w/ almost anything
Group V mostly nonmetals
Important- N, P & As
Have -3 ion charge

14. Groups 6 & 7 Group VI Chalcogens
Chalkos - greek made of copper (O & S make up most Cu)
Have -2 ion charge
Good acid makers
Important - O, S, Se
Group VII - Halogens
Halos - greek for salt, most salts are halogen
Important - F, Cl, Br, I
Have -1 ion charge

15. Group 8 Noble Gases Only group that all are gases at room temp.
Very stable, hard to form compounds
Have 0 ionic charge
Bonds weakly w/ same element
Important - He, Xe, Ar, Rn
Poor conductors

16. Transition Metals All the metals in the middle All are +2 ion charge
Good conductors of heat & electricity
Ductile - made into wires
Malleable - can be shaped
Include Actinides & Lanthanides (mostly manmade)
Important - Fe, Ag, Au, Hg, Cr, Mn, Cu

17. Periodic Trends Atomic Size Size increases down a group
Size increases from right to left across a period

18. More Trends
Ionization Energy (IE) - amount of heat or energy needed to make an elemental ion
IE decreases down a group
IE increases from left to right in periods
More electrons moving from left to right

19. Important Elements to Know
H - Hydrogen
C - Carbon
O - Oxygen
N - Nitrogen
S - Sulfur
He - Helium
Al - Aluminum
Cl - Chlorine
Fe - Iron
Hg - Mercury
Au - Gold
Ag - Silver
K - Potassium
Na - Sodium
Pb - Lead
Sn - Tin