OUTLINE of TOPICS 1. The Story of Atom 2. Subatomic Particles 3. J.J. Thomson 4. Milikan Middle School 5. E. Rutherford 6. The Periodic Table 7. Counting on Atom

1. The Story of Atom 1. What are some major components in a story? 2. What are some things that all stories must have?

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

1. The Story of Atom

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.

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

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

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.

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

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.

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

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

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

1. The Story of Atom 1. Democritus 2. Alchemists during the Middle Ages – wanted to convert one element to another th and 17 th century; 1500’s – 1600’s th century: 1700’s – 1800’s

1. The Story of Atom th and 17 th 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.

1. The Story of Atom th and 17 th 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

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

1. The Story of Atom th 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.

1. The Story of Atom th 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.

1. The Story of Atom th 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?

1. The Story of Atom th 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

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

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

1. The Story of Atom th century; 1700’s Joseph Proust – glucose is the same, C 6 H 12 O 6, 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…

1. The Story of Atom th 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 C 6 H 12 O 6 H 2 O will always be made up of 2 H and 1 O

1. The Story of Atom th 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?

1. The Story of Atom th 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

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

1. The Story of Atom Compound Mass of Element(g) A25 B50

1. The Story of Atom Compound Mass of Element(g) A0.200

1. The Story of Atom Compound Mass of Element(g) A0.200 B0.400

1. The Story of Atom Compound Mass of Element(g) A0.200 B0.400 C0.600

1. The Story of Atom Compound Mass of Element(g) A0.200 B0.400 C0.600 D

1. The Story of Atom Compound Mass of Element(g) A0.200 B0.400 C0.600 D0.800

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

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

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.

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?

1. The Story of Atom

Dalton’s Atomic Theory of Matter 1. All matter is composed of small particles called ATOMs, which cannot be divided 2. Atoms of a given element/compound are identical in their physical and chemical properties, does not matter where they are from. 3. Atoms of the same elements are identical, and different elements have different types of atoms 4. Atoms of different elements combine in simple, whole- number ratios to form compounds 5. In chemical reactions, atoms are combined, separated, or rearranged but never created, destroyed, or changed

1. The Story of Atom Dalton’s Atomic Theory of Matter 1. All matter is composed of extremely small particles called ATOMs, which cannot be subdivided - DEMOCRITUS 2. Atoms of a given element are identical in their physical and chemical properties – LAW OF DEFINITE PROPORTIONS 3. Atoms of the same elements are identical, and different elements have different types of atoms – BOYLE 4. Atoms of different elements combine in simple, whole- number ratios to form compounds – LAW OF MULTIPLE PROPORTIONS 5. In chemical reactions, atoms are combined, separated, or rearranged but never created, destroyed, or changed – LAW OF CONSERVATION OF MASS

1. The Story of Atom Summary & Review 1. Democritus is important because… 2. Dalton is important because… 3. Law of Conservation of Mass means… 4. 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?