Transcript Atomic Structure - Physical Science

Atomic Structure
3 Parts of the Atom:
Subatomic
Particle
Proton
Relative Mass
Charge
Where Found
1
+1
In Nucleus
Neutron
1
0(neutral)
In Nucleus
Electron
0
-1
Outside
nucleus in
electron cloud
Key Points:
•The nucleus of an atom contains roughly 99.9% of the mass of an atom.
•More than 99.9% (that's a popular number) of the atom is "empty space"
occupied by moving electrons (which weigh very little). If you could make an
atom as big as a football stadium, then its nucleus would still be as small as a
marble.
•We cannot predict the exact location—only a probable location—of an electron
at any given time.
•Electrons in the outer energy levels(called valence electrons) are
involved with forming compounds.
What is the relative mass of a proton?
A. O
B. 1
C. 2
D. 3
What is the charge of an electron?
A. Positive
B. Negative
C. Neutral
What subatomic particle has a
relative mass of 1 and a (+) charge
A. Electron
B. Proton
C. Neutron
What subatomic particle(s) are
found inside the nucleus?
A. Electron
B. Proton
C. Neutron
D. Protons and Neutrons
E. Protons and Electrons
Each energy level can hold a specific #
of electrons:
How many electrons are found in the
3rd energy level?
A.
B.
C.
D.
E.
0
2
8
10
18
How do we know so
much about the atom?
Who discovered the
atom? How long ago?
It started along time ago with
a guy named Democritus and
went through several changes
until a couple of dudes
named de Broglie and
Schrodinger
I hope we
get a
handout
with all
these
names!!
I look pretty
good for a
dude 2400
years old!!!
In Greek, the prefix "a" means "not" and the
word "tomos" means cut. Our word atom
therefore comes from atomos, a Greek word
meaning uncuttable.
John Dalton: early 1800’s
JJ Thomson--1897
Plum Pudding Model
But the
atom is
Neutral!!!!
While studying electric
discharge in Cathode-ray tubes,
Thomson discovered the
electron!!!
Ernest Rutherford--1908
Rutherford’s Gold Foil Experiment
In an attempt to build on Thomson’s
model, I discovered some amazing
stuff!!!
What
Rutherford
Expected
Actual
Results
Rutherford’s
Model
Notice 2 things:
1. Atom is made
up of mostly
empty space.
2. Electrons are
scattered
randomly!
Rutherford’s Atomic Model
Nucleus
Electrons
Neils Bohr--1913
Bohr Model of the Atom
The Bohr Model has the following features:
1. There is a nucleus(Rutherford’s Discovery)
2. The electrons move about the nucleus in “stationary,
stable states”(later referred to as orbits)!
The Wave Model of the Atom
Discovery of the neutron
James Chadwick--1932
In 1932, Sir James
Chadwick, working
to interpret the
results of other
scientists,
discovered the
neutron!!!
Which scientist is credited with the
discovery of the electron?
A. Dalton
B. Thomson
C. Rutherford
D. Bohr
Which scientist is credited with the
discovery of the “orbital” motion of
the electrons around the nucleus?
A. Dalton
B. Thomson
C. Rutherford
D. Bohr
Which scientist is credited with the
discovery of the nucleus?
A. Dalton
B. Thomson
C. Rutherford
D. Bohr
Which scientist is credited with the 1st
Atomic Theory?
A. Dalton
B. Thomson
C. Rutherford
D. Bohr
I’m going to find
Mr. Rodgers
Mrs. Hardeman
Mrs. Wolcott
Mrs. Elliot
Let’s
wrap this
up!!!
That’s a
bunch of
stuff!!!
Mrs. Hatfield
Democritus/Dalton
Chemical Symbols
• Shorthand method of writing the names of
the elements on the period table.
– All symbols either have 1 or 2 letters.
• If one letter, then that letter is capitalized.
• If two letters, then first letter is capitalized, second
letter is lowercase.
• H—Hydrogen
• Cu—Copper
• Cl—Chlorine
C-Carbon
Mg—Magnesium
K-Potassium
Classwork
•P. 511 #1-5