1. Sections 4-1,4-2 Video #7 (The history of atomic chem CC)
Chapter 4 Notes (4)
Sections 4-1,4-2
Video #7 (The history of atomic chem CC)

2. I.Development of an Atomic Model
*Matter:
anything that has mass and volume
 *Indirect Evidence:
evidence you get without actually seeing or touching the object

3. -Greek Model (Democritus)
*atom:
smallest particle of an element that has the prop of the element
~atomos:
meaning not to be cut

4. -Dalton’s Atomic Theory
1. All elements are composed of atoms
2. Atoms of the same element are exactly alike

5. 3. Atoms of diff. elements are diff.
4. Compounds are formed by joining of atoms of 2 or more elements

6. II. A Divisible Atom -Thomson’s Model: ~Plum Pudding
*Electrons: - charge
#45(JJ Tomson)

7. -Rutherford’s Model
~Gold Foil Experiment
~the atom was mostly empty space with a dense, positively charged nucleus in the center.
*Nucleus:
the center of the atom

8. ~electrons move in definite orbits around the nucleus
-Bohr Model
~electrons move in definite orbits around the nucleus

9. -Wave Model (Today accepted model)
~electrons don’t move about in a definite path
~probable location is based on how much nrg the electron has

10. SEE HISTORY OF THE ATOM WEBSITE

11. III. Subatomic Particles
*smaller than the atom

12. -Three main subatomic part.
1.     proton
2.     neutron
3.     electron
**quarks (make up 1 & 2)**

13. -Nucleus
*center of the atom

14. ~proton: 1 + nucleus ~neutron: 1 +/- nucleus
mass (amu) charge location
~proton: nucleus
~neutron: /- nucleus
~electron: 1/ e- cloud

15. *Atomic Mass Unit (amu):
measures mass of subatomic part.
-?? Where does it come from??

16. -Atomic #
*number of + in the nucl
~identifies the element
~never chngs

17. *same # of +, but diff # of neutrons EX: -Mass # and Atomic Mass
-Isotopes
*same # of +, but diff # of neutrons
  EX:
-Mass # and Atomic Mass
*sum of the + and neutrons in its nucleus

18. *Aver Atomic mass:
aver of the masses of all the atoms in the sample.
~mass # - atomic# = #of neutrons

19. III. stop
3 H Nuclear Notation 1
Hydrogen Hyphenated Notation

20. III. continue *e- cloud: place in which e-’s are likely to be found
-Electrons (e-)
*e- cloud:
place in which e-’s
are likely to be found
~location depends upon how much nrg the e- has

21. *nrg levels:
most likely location of the e-
  ~2,8,8.
*Valence e-:
e- outer most nrg
level

22. ~Movement of e-’s:
-in: lose nrg
-out: gain nrg

23. IV. Forces Within the Atom
#9(The weak and strong nuclear force)
-The four forces that account for the behavior of sub part
1.     electromagnetic force
*either attract or repel particles

24. 2.     strong force
*opposes electromag force of repulsion between +
~only when + are very close together

25. *key to the power of the sun ~responsible for radioactive decay
3.     weak force
*key to the power of the sun
~responsible for radioactive decay
~ +/ > + and -

26. 4.     gravity
*weakest force known in nature
~force of attraction exerted between all objects