The Story of Atom: Concepts, Laws, and Models

1. October 9, 2014 What are the two concepts and three laws Dalton tried to explain? Explain the three laws How are Thomson and Rutherford’s model different from one another? Which subatomic particle tells us the identity of an atom? What do the atomic and mass numbers tell us? A painter hand paints the dots on a dice. In one hour, the painter paints 30 dots. How many dots does he paint in 20 minutes?

2. Agenda October 9, 2014 • 6. Finish The Periodic Table • 7. Counting on Atom • Review Unit • HOMEWORK

3. OUTLINE of TOPICS The Story of Atom Subatomic Particles J.J. Thomson Millikan Middle School E. Rutherford Counting Atoms Periodic Table

4. 1. The Story of Atom What are some major components in a story? What are some things that all stories must have?

5. 1. The Story of Atom How we know what we know about the Atom OBJECTIVE: Understand the development of how the idea of an “atom” came about

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8. 1. The Story of Chemistry In order to understand WHY we know and HOW we know this is what an atom looks like, we need to learn about the story of the atom.

9. 1. The Story of Chemistry Early human civilizations organized “stuff” into four categories: Earth, Air, Fire, Water

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11. 1. The Story of Atom The first known writing that has the word “ATOM” is from Greece. It was written around 400 B.C. by a philosopher named Democritus, Δημόκριτος

12. 1. The Story of Atom Democritus’ idea was… Everything that exists is made up of this “thing.” This thing cannot be separated or divided into something smaller. He called this thing an ATOM.

13. 1. The Story of Atom ATOM = a Greek word Temnein = to cut or divide a = prefix meaning not a + temnein = atom atom = unable to cut

14. 1. The Story of Atom Democritus’ idea was… Everything that exists is made up of this “thing” that cannot be broken, separated, or divided into something smaller. He called that “thing” an ATOM.

15. 1. The Story of Atom Democritus’ idea of the atom is… An observation? A hypothesis? An experiment? A law? A theory?

16. 1. The Story of Atom Democritus’ idea of the atom is… A hypothesis because his idea could not be tested.

17. 1. The Story of Atom IMPORTANT!!! Democritus’ idea of atom =/=

18. 1. The Story of Atom • Democritus • Alchemists during the Middle Ages – wanted to convert one element to another. • 16th and 17th century; 1500’s – 1600’s • 18th century: 1700’s – 1800’s

19. 1. The Story of Atom • 3. 16th and 17th century; 1500’s – 1600’s • Robert Boyle – worked with gases, and looked at pressure and volume. • Robert Boyle is important because he came up with the idea, the concept, of an ELEMENT.

20. 1. The Story of Atom 3. 16th and 17th century; 1500’s – 1600’s Robert Boyle is important because he came up with the idea, the concept, of an ELEMENT. Now that we knew about ELEMENTS, people began to identify many things as elements. Most of these “things” were metals

21. 1. The Story of Atom 4. 18th century; 1700’s Antoine Lavoisier

22. 1. The Story of Atom 4. 18th century; 1700’s Antoine Lavoisier – saw that when a chemical change takes place, the mass does not change. something cannot be made from nothing, and something cannot become nothing.

23. 1. The Story of Atom 4. 18th century; 1700’s Antoine Lavoisier – saw that when a chemical change takes place, the mass does not change. mass cannot be created or destroyed during a chemical or physical change.

24. 1. The Story of Atom 4. 18th century; 1700’s “mass cannot be created or destroyed during a chemical or physical change.” Is this an observation? Is this a hypothesis? Is this an experiment? Is this a law? Is this a theory?

25. 1. The Story of Atom 4. 18th century; 1700’s “mass cannot be created or destroyed during a chemical or physical change.” It is a law because it is a statement about WHAT nature does. Law of Conservation of Mass/Matter

26. 1. The Story of Atom 4. 18th century; 1700’s Antoine Lavoisier is important because he showed that mass/matter cannot be created or destroyed.

27. 1. The Story of Atom 4. 18th century; 1700’s Joseph Proust -

28. 1. The Story of Atom 4. 18th century; 1700’s Joseph Proust – glucose is the same, C6H12O6, and it doesn’t matter it if is from grapes, honey, oranges, or apples because glucose will ALWAYS have 6 C’s, 12 H’s, and 6 O’s. Or, to summarize this in your notes…

29. 1. The Story of Atom 4. 18th century; 1700’s Joseph Proust – Joseph Proust – a compound always contains the same elements, and exactly the same amount in mass. Example Glucose will always be made up of C6H12O6 H2O will always be made up of 2 H and 1 O

30. 1. The Story of Atom 4. 18th century; 1700’s Joseph Proust – a compound always contains the same elements, and exactly the same amount in mass. Example H2O will always be made up of 2 H and 1 O Which part of the S.M. does this belong?

31. 1. The Story of Atom 4. 18th century; 1700’s Joseph Proust – a compound always contains the same elements, and exactly the same amount in mass. Example H2O will always be made up of 2 H and 1 O Which part of the S.M. does this belong? It is a law. Law of Definite Proportions

32. 1. The Story of Atom 4. 18th century; 1700’s John Dalton

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39. 1. The Story of Atom John Dalton Law of Multiple Proportion

40. 1. The Story of Atom John Dalton Law of Multiple Proportion

41. 1. The Story of Atom John Dalton Law of Multiple Proportion – when elements form two or more compounds, the mass of one element that combines with a mass of the other is in the ratio of small whole numbers.

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43. 1. The Story of Atom John Dalton is important because he took all the important ideas/laws and tried to explain them using the concept of an atom. He proposed a theory that all matter is made up of indivisible things called atoms. He called this theory THE ATOMIC THEORY OF MATTER Why is his idea a theory and not a law?

44. 1. The Story of Atom

45. 1. The Story of Atom Dalton’s Atomic Theory of Matter All matter is composed of small particles called ATOMs, which cannot be divided Atoms of a given compound are identical in their elements and amount in mass, does not matter where they are from. Atoms of the same elements are identical, and different elements are made up of different types of atoms Compounds that are made up of the same elements but just different amounts have mass ratios in whole-numbers In chemical reactions, atoms are combined, separated, or rearranged but never created, destroyed, or changed

46. 1. The Story of Atom • All matter is composed of small particles called ATOMs, which cannot be divided. • ATOM • Atoms of a given compound are identical in their elements and amount in mass, does not matter where they are from. • LAW OF DEFINITE PROPORTION • Atoms of the same elements are identical, and different elements are made up of different types of atoms • ELEMENT • Compounds that are made up of the same elements but just different amounts have mass ratios in whole-numbers • LAW OF MULTIPLE PROPORTION • In chemical reactions, atoms are combined, separated, or rearranged but never created, destroyed, or changed • LAW OF CONSERVATION OF MASS

48. 1. The Story of Chemistry Summary & Review Democritus is important because… Dalton is important because… Law of Conservation of Mass means… When a log completely burns in a campfire, the mass of the ash is much less than the mass of the log. What happened to the “missing” mass? The question above is related to which of the three laws?

49. What does it mean for a submarine to “submerge” underwater? What are “sub”-atomic particles? 2. Subatomic Particles

50. 2. Subatomic Particles OBJECTIVE:Proton, Neutron, Electron