![Page 1: Atomic Theory. Ancient Greeks Democritus’ idea (theory) was: All matter is made of small pieces that cannot be divided any smaller. The word ATOM means](https://reader036.vdocuments.us/reader036/viewer/2022070401/56649f1a5503460f94c2fec9/html5/thumbnails/1.jpg)
Atomic Theory
![Page 2: Atomic Theory. Ancient Greeks Democritus’ idea (theory) was: All matter is made of small pieces that cannot be divided any smaller. The word ATOM means](https://reader036.vdocuments.us/reader036/viewer/2022070401/56649f1a5503460f94c2fec9/html5/thumbnails/2.jpg)
Ancient Greeks
• Democritus’ idea (theory) was: All matter is made of small pieces that cannot be divided any smaller.
• The word ATOM means “indivisible”
Just an idea, no “picture” of what the atom looks like.
![Page 3: Atomic Theory. Ancient Greeks Democritus’ idea (theory) was: All matter is made of small pieces that cannot be divided any smaller. The word ATOM means](https://reader036.vdocuments.us/reader036/viewer/2022070401/56649f1a5503460f94c2fec9/html5/thumbnails/3.jpg)
Dalton’s Theory
Theory: All matter is made up of individual particles called atoms, which cannot be created, divided, or destroyed. (sound familiar?)
Features:
1. Solid, no “insides”.
2. Atoms of the same element are exactly alike.
(1803)
![Page 4: Atomic Theory. Ancient Greeks Democritus’ idea (theory) was: All matter is made of small pieces that cannot be divided any smaller. The word ATOM means](https://reader036.vdocuments.us/reader036/viewer/2022070401/56649f1a5503460f94c2fec9/html5/thumbnails/4.jpg)
Thomson’s Theory
Theory: Atoms CAN be divided into smaller pieces. [“Chocolate Chip Cookie Model”]
Feature:
1.Discovered the negatively charged ELECTRON.
(1897)
electrons
![Page 5: Atomic Theory. Ancient Greeks Democritus’ idea (theory) was: All matter is made of small pieces that cannot be divided any smaller. The word ATOM means](https://reader036.vdocuments.us/reader036/viewer/2022070401/56649f1a5503460f94c2fec9/html5/thumbnails/5.jpg)
Rutherford’s Theory
Theory: Atoms are mostly empty space.[Gold Foil Experiment]
Feature: Proved that atom has POSITIVELY charged NUCLEUS
The Gold Foil Experiment (He shot a stream of positive particles at piece of gold foil- most went straight through and only a few bounced back- this proved that atoms were mostly EMPTY SPACE, the ones that bounced had hit a small solid center, the nucleus.)
(1911)
+
-
-
-
-
-
- -
nucleus
![Page 6: Atomic Theory. Ancient Greeks Democritus’ idea (theory) was: All matter is made of small pieces that cannot be divided any smaller. The word ATOM means](https://reader036.vdocuments.us/reader036/viewer/2022070401/56649f1a5503460f94c2fec9/html5/thumbnails/6.jpg)
Gold Foil Experiment
Thomson
Rutherford
![Page 7: Atomic Theory. Ancient Greeks Democritus’ idea (theory) was: All matter is made of small pieces that cannot be divided any smaller. The word ATOM means](https://reader036.vdocuments.us/reader036/viewer/2022070401/56649f1a5503460f94c2fec9/html5/thumbnails/7.jpg)
Bohr’s Theory
Theory: Electrons move around outside the nucleus in specific patterns called ENERGY LEVELS.
Feature: Electrons orbit around nucleus in specific paths, just like planets around the Sun in the solar system.
(1913)
What does this remind you of?
Energy levels
![Page 8: Atomic Theory. Ancient Greeks Democritus’ idea (theory) was: All matter is made of small pieces that cannot be divided any smaller. The word ATOM means](https://reader036.vdocuments.us/reader036/viewer/2022070401/56649f1a5503460f94c2fec9/html5/thumbnails/8.jpg)
Electron Cloud (Quantum) Model
Theory: Predicts where electrons MAY be located in an atom. [*Closest to what we think the atom is today!*]
Feature: Cannot know exactly where the electrons are at any time, they are “in the cloud”.
(1926)
+
-
-
-
-
-
-
-
Electrons anywhere at any time
![Page 9: Atomic Theory. Ancient Greeks Democritus’ idea (theory) was: All matter is made of small pieces that cannot be divided any smaller. The word ATOM means](https://reader036.vdocuments.us/reader036/viewer/2022070401/56649f1a5503460f94c2fec9/html5/thumbnails/9.jpg)
THE BIG IDEA
As technology has improved, our idea of the ATOM has changed over time.
(our models have gotten better!)
![Page 10: Atomic Theory. Ancient Greeks Democritus’ idea (theory) was: All matter is made of small pieces that cannot be divided any smaller. The word ATOM means](https://reader036.vdocuments.us/reader036/viewer/2022070401/56649f1a5503460f94c2fec9/html5/thumbnails/10.jpg)
Video Links
• History of Atomic Theory Song – Veritasium
• The History of Atomic Chemistry: Crash Course Chemistry #37