interactive lecture – kandace little
LET’S MAKE A FIRST WORD
BASED ON WHAT WE KNOW

FIRST WORD: ATOM
A
T
O
M
THE BEGINNINGS


I’m going to take you back to 350 B.C….
Aristotle
…

earth
…

water
…

fire
…

air
…

 Aristotle asks you: “Can you deny that these are the
fundamental elements of the earth, Ruler?”
 Your reply?
 Alas, after deep thinking, you are convinced that this
wise philosopher is correct. Aristotle has made
observations about life and this is his THEORY to
explain those observations.
Jumping to 300 A.D...

GOLD
Lead
Tin
…

 The alchemists are inspired by Aristotle’s ideas and
are trying to turn cheap metals into GOLD!
 The news article says that even though the Pope
issued that no gold-making occurred, the gold
business continued.
 However, despite the alchemists efforts, they were
unsuccessful in changing cheap metals into gold.
A little later on..

GOLD
BREAKING NEWS: NEW THEORY FOUND!
-All matter is made of atoms.
-Atoms of an element are identical.
-Each element has different atoms.
-Atoms of different elements combine in constant
ratios to form compounds.
-Atoms are rearranged in reactions.
LAW OF CONSERVATION OF MASS
John Dalton = new hero
2 p+
2 n0
Boyle, Crookes, Becquerel, Thomson, Rutherford,
Chadwick
 John Dalton states the
Atomic Theory
Dalton’s “Billiard Ball” model

 Atoms are solid and indivisible.
Thompson Plum Pudding model

 Negative electrons in a positive framework
To show this is a positive framework
The Rutherford Model

 Atoms are mostly empty space.
 Negative electrons orbit a positive nucleus.
Bohr-Rutherford Model

 Putting all this together, we get Bohr-Rutherford
diagrams that look like this:
2 p+
2 n0
3 p+
4 n0
LET’S MAKE A LAST WORD BASED
ON WHAT WE KNOW NOW

LAST WORD: ATOM
A
T
O
M
References

 Chalkbored found at www.chalkbored.com
 History of Chemistry found at
http://www.columbia.edu/itc/chemistry/chemc2507/navbar/chemhist.html