Chapter 4 Notes: Atoms
What do I know What do I want to know What have I learned
Scientists and the Historic path to the Model of an Atom:
Scientist Evidence Model Drawing
Back in the old days…..
Aristotle: Everything is made up of:
But Thanks to Dalton we know……
Daltons Atomic Theory: Example
Now what exactly does the atom look like???
Thompson’s Adventures to find the ELECTRON ( e- )
Drawing: Blyth’s Example :
Thompson’s Plum Pudding Model: Drawing
Question? How do objects of the same charge behave when they come close together?
Drawing of Demo:
Atomic Model progressing….
Rutherford’s experiment: He discovered ___________________________
Experiment- which lead to….. Model of the Atom:
Expected results Drawing What they thought
Actual (Oh my Gosh!) Drawing What they thought
Let’s Look inside the atom now….
4.2 If an atom is made up of sub-atomic particles what are they, and what should I
know about them?
What do I know What do I want to know What have I learned?
Atomic Structure: Inside the Atom
Particle Charge and Where is it? Size
Periodic Table and how it helps us…
Atomic Number Atomic symbol and Name Mass Number
These Three pieces of information can be used to help you develop a model of each atom
on the periodic table.
I Do We Do You do
Carbon: Oxygen: Nitrogen:
Sulfur: Phosphorous: Boron:
Atomic Model Drawings: Now let’s use the Data in the table above to create a model of
Rules for Models of I do We do You do
1. Use Name or Carbon has the symbol Oxygen Sodium
Symbol to find capitol C in periodic
element on Periodic table.
2. Use Atomic
determine number 6
of Protons AND C
3. To Find number Mass Number –Atomic Number=
Number of Neutrons
subtract the Atomic 12 - 6 = 6 Neutrons
number from the
4. Draw correct
amount of rings
according to the
2 e – 1st ring
8 e – 2nd ring
18 e – 3rd ring
32 e – 4th ring
Q 2? How can these models look different if there is a
change in the numbers?
Isotopes: These are elements that have the same
charge and number of protons and electrons as
the elements on periodic table BUT they are
lighter or heavier due to a different number of
Carbon has an Isotope we call Carbon-14. These
means that there are 2 more ________ in the
Nucleus of this Carbon than the one on the
C 12 now becomes C 14
What about another isotope? Oxygen 18?
O 16 now becomes O 18
4.3 Modern Atomic Model – Bohr’s model
Bohr focused on the location of the ____________ in the atom.
Bohr coined the Phrase ________________to stand for the possible
energies that an electron could have in an atom.
Ground Can you go up or down half of a
Movement of the _____________ must occur in these set energy
levels. NO HALF WAY! To jump up a step they need to Gain
(Absorb) _________. To Jump down (emission) a step they must
________ energy. (Usually in the form of Light )
Mrs. Miller’s Demo:
Electron Cloud Model: The famous picture
A Fan blade is a good example of how we cannot know
the location of an electron because:
This Modern Model is the most up to date picture of an atom. We can never
know the _______________ of an electron, just the __________ of finding
an electron in a given energy level.