1. Chapter 4.1 An Atomic Model of Matter
The Greek Model
Dalton’s model
Thompson’s model
Rutherford’s model
Bohr’s model
Modern model
How Elements Are Formed Clip

2. The Greek model
Democritus said that matter could not be divided into smaller and smaller pieces forever. He proposed the atom or Atomos meaning –not divisible
These philosophers were called Atomist

3. Indirect Evidence
The atomist only had indirect evidence they did not have microscopes…
This is evidence that you get without seeing or touching it

4. Dalton’s Model Daltons proposed a 4 part theory about atoms
1. All elements are Composed of atoms
2. Atoms of the same element are alike
3.Atoms of different elements are different
4. Compounds are formed by the joining of 2 or more elements

5. Thomson’s Model
According to Thomson the atom was made of a pudding like positively charged material throughout which negatively charged electrons were scattered like plums in pudding.

6. Rutherford’s Model
Rutherford said that the positive particles were contained in the nucleus and the negative charged particles were scattered outside

7. The Gold Foil Experiment Clip

8. Bohr’s Model
Bohr stated that electrons orbited around the nucleus like planets around the sun and each orbit was a different energy level.

9. The Modern Model
Electrons are behaving more like waves than planets and they vibrate back and forth.
They are like bees around a hive.
History Timeline of the Atom

10. Building blocks of molecules
Atoms are the smallest part of an element that acts like that element
Atoms are composed of 3 smaller particles: Protons, electrons and neutrons.

11. Democritus
Modern

12. Modern Model of Atom