1. November 28th Homework: read pgs 112 - 118 Take the two worksheets.
Write down your homework
Answer the Quick Write on the worksheet.
SWBAT:
Summarize each scientist and philosopher’s addition to the development of the structure of the atom.
Homework:
read pgs

2. The History of The Atom
Introduction_to_the_Elements.mov

3. November 30th Homework: SWBAT: Quick Write:
Summarize each scientist and philosopher’s addition to the development of the structure of the atom.
Explain the forces within an atom.
Quick Write:
How are electrons kept in orbit around the nucleus?
What descriptive words can you use to describe Niels Bohr and his model of the atom?
Homework:
review your notes and highlight key terms and complete the video worksheet

4. Aristotle Democritus Greek philosopher
Believed that there were only four elements:
water
fire
Earth
air
Greek philosopher
Believed that matter cannot be divided into small pieces forever.
He named the smallest piece an atomos,
Atomos is Greek for atom.
Atomos means indivisible.
Atom: the building block of all matter.

5. The Proposed Atomic Theory, by Dalton
All elements are composed of atoms. Atoms are indivisible and indestructible.
Atoms of the same element are exactly alike.
Atoms of different elements are not alike.
Compounds are formed by the joining of atoms of two or more elements.

6. Thomson’s Model
In 1897, Thomson proposed that the atom maybe made of even smaller particles.
He explained that there were positive charges in the atoms and negative charges scattered throughout.
”plum pudding”

7. Rutherford’s Model
Conducted an experiment concluding that the atom was mostly empty space filled with positive charges.
Proposed that the positive charged particles were in the center of the atom, called the nucleus.
Outside the nucleus were negative electrons scattered throughout the edge of the atom.

8. Niels Bohr
In 1913, Bohr believed that the electrons traveled in a definite orbit with a certain energy level and certain distance from the nucleus.
Each energy level can hold a certain amount of electrons.

9. December 1st Homework: SWBAT: Quick Write:
Identify where each electron is found according to the Bohr model.
Draw and identify your mystery atoms!
Quick Write:
What are the four forces of the atom.
Which is the strongest force
What does it act as? Explain
Homework:
Finish Bohr Model worksheet
Look up the use of each element you identified on your Bohr Model worksheet.
bring in the all completed class work from Tuesday tomorrow.

10. Modern Atomic Model
Today we believe that the electrons do not travel a certain path.
They do have a certain energy level.
They are always moving

11. The Bohr Model
According to the Bohr model each energy level can hold a certain number of electrons.
Starting from the first level outside of the nucleus:
Level 1: can hold 2 electrons
Level 2: can hold 8 electrons
Level 3: can hold 18 electrons
Level 4: can hold 32 electrons
Level 5: can hold 32 electrons

12. Look at the examples below:
Second
shell
Helium
2He
First
Third
Hydrogen 1H 2 He
4.00
Atomic mass
Atomic number
Element symbol
Electron-shell
diagram
Lithium
3Li
Beryllium
4Be
Boron 3B
Carbon 6C
Nitrogen 7N
Oxygen 8O
Fluorine 9F
Neon
10Ne
Sodium
11Na
Magnesium
12Mg
Aluminum
13Al
Silicon
14Si
Phosphorus
15P
Sulfur
16S
Chlorine
17Cl
Argon
18Ar
Figure 2.8

13. Closure
Draw your samples on the board!

14. Forces Within
Electromagnetic force: is an attraction or repulsion between particles.
If the particles have the same charge they are repelled.
If the particles have opposing charges they are attracted to each other.
Strong Force

15. Weak Force:
Gravity:

16. Closure Which force is the weakest and why?
Which two forces keep the atom’s strucutre?