1. Get Ready! Materials Today’s Agenda 5-in-5 Atomic Theory Video
Pencil
Notebook
5-in-5
Atomic Theory Video
Atomic Theory Timeline

2. 5-in-5 #15

3. What am I going to learn today?
I will…
At the end of the lesson I will be able to…
understand the Atomic Theory has changed over time as scientists have discovered new information about the atom.
write a 5 paragraph essay summarizing the contributions of scientists to the Atomic Theory.

4. Introduction Video
History of the Atomic Theory

5. Timeline Activity
Complete the timeline activity with a partner.

6. Get Ready! Materials Today’s Agenda 5-in-5 Atomic Theory Notes Essay
Pencil
Notebook
5-in-5
Atomic Theory Notes
Essay
Exit Ticket

7. 5-in-5
What are three things you learned from completing the atomic theory timeline?

8. What am I going to learn today?
I will…
At the end of the lesson I will be able to…
understand the Atomic Theory has changed over time as scientists have discovered new information about the atom.
write a 5 paragraph essay summarizing the contributions of scientists to the Atomic Theory.

9. Scientists and Their Contribution to the Model of the Atom
History of the Atom
Scientists and Their Contribution to the Model of the Atom

10. History of the Atom - Timeline
J.J. Thomson discovers the electron and proposes the Plum Pudding Model in 1897
Niels Bohr proposes the Bohr Model in 1913
James Chadwick discovered the neutron in 1932
1766 – 1844
1871 – 1937
1887 – 1961
460 – 370 BC
1700s
1800s
1900s
Erwin Schrodinger describes the electron cloud in 1926
Democritus proposes
the 1st atomic theory
John Dalton proposes his atomic theory in 1803
Ernest Rutherford performs the Gold Foil Experiment in 1909
1891 – 1974
1885 – 1962
1856 – 1940

11. Democritus (460 BC – 370 BC)
Proposed an Atomic Theory which states that all atoms are small, hard, indivisible and indestructible particles made of a single material formed into different shapes and sizes.
Aristotle DID NOT support his atomic theory, so his ideas were not shared.

12. John Dalton (1766 – 1844)
In 1803, proposed an Atomic Theory which states:
All matter is made of atoms; small particles that cannot be created, divided, or destroyed.
Atoms of the same element are exactly alike, and atoms of different elements are different.
Atoms join with other atoms to make new substances.

13. J.J. Thomson (1856 – 1940)
Proved that an atom can be divided into smaller parts
While experimenting with cathode-ray tubes, discovered corpuscles, which were later called electrons
Stated that the atom is neutral
In 1897, proposed the Plum Pudding Model which states that atoms mostly consist of positively charged material with negatively charged particles (electrons) located throughout the positive material.

14. J.J. Thomson Cathode Ray Experiment

15. Ernest Rutherford (1871 – 1937)
In 1909, performed the Gold Foil Experiment and suggested the following characteristics of the atom:
It consists of a small core, or nucleus, that contains most of the mass of the atom
This nucleus is made up of particles called protons, which have a positive charge
The protons are surrounded by negatively charged electrons, but most of the atom is actually empty space

16. Gold Foil Experiment

17. Niels Bohr (1885 – 1962)
In 1913, proposed the Bohr Model, which suggests that electrons travel around the nucleus of an atom in orbits (shells, levels) or definite paths.

18. Erwin Schrodinger ( )
In 1926, he further explained the nature of electrons in an atom by stating that the exact location of an electron cannot be stated; therefore, it is more accurate to view the electrons in regions called electron clouds.
Electron clouds are places where the electrons are likely to be found

19. James Chadwick (1891 – 1974)
Realized that the atomic mass of most elements was double the number of protons, which led to the discovery of the neutron (neutral particle) in 1932.

20. Democritus & John Dalton
Progression of the Atomic Model + -
The structure of an atom, according to:
Democritus & John Dalton
James Chadwick
J.J. Thomson
Neils Bohr
Ernest Rutherford
Erwin Schrodinger

21. Atomic Theory Essay How has the Atomic Theory changed over time?
Writing Prompt:
How has the Atomic Theory changed over time?
Complete the essay independently.
You may use your notes, timeline and textbook.
Be sure to include the scientists, their research and ideas about what an atom looks like.

22. 3·2·1 Exit Ticket
3 things I learned were…. 2 things I thought was interesting/surprising were…. 1 thing I still have a question about is….