1. Please copy your homework into your assignment book
BEFORE THE BELL RINGS
Please copy your homework into your assignment book
Please have your vocabulary out to check
C. Johannesson

2. What is the particle composition of an atom?
What is the structure of an atom?
What is a subatomic particle?
Where are these located?

3. Monday, November 7, 2016 Warm-up Atomic Theory Notes
Laws graphic organizer
Pg. Read pgs74 – 77: answer concept check questions on pg. 77 in complete sentences.
Homework: Chapter 2 Test Corrections Due Wednesday.

4. How do we know atoms exist? Section 3-1
Atomic Structure

5. Scientific Laws
A scientific law is a statement or mathematical expression that reliably describes the behavior of the natural world.

6. Scientific Theory
A scientific theory is a broad generalization that is based on observation, experimentation, and reasoning.
Because theories are not facts, but rather explanations, they can never be completely proven.

7. Atomic Theory
Evidence for the existence of atoms is built upon three scientific laws:
Law of definite proportions
Law of conservation of mass
Law of multiple proportions

8. Law of Definite Proportions
A given compound contains the same elements in exactly the same proportions by mass, regardless of the size of the sample or the source of the compound.

9. Law of Definite Proportions
Example:
Sodium Chloride (table salt)
Regardless of how much we have is always:
39.34% by mass of sodium
60.66% by mass of chlorine Cl Na Or

10. Law of Conservation of Mass
The products of a chemical reaction have the same mass as the reactants.

11. Law of Conservation of Mass
Example:
Sulfur Oxygen → Sulfur dioxide
32.07 g g → g
Reactants Products O S S + O →

12. Law of Multiple Proportions
Different compounds can be formed from the same elements in different proportions.

13. Law of Multiple Proportions
Example:
H2O Water H2O2 Hydrogen Peroxide H O H O O H

14. Graphic Organizer Fold a sheet of paper into thirds
Label each column with one of the three laws we just discussed
Define the law
Give an example from your textbook of the law (draw the example and explain the example)
When you complete this turn the sheet over and answer questions 1&2 on pg. 77 in complete sentences.

15. Chapter 2 Test Corrections
You may complete test corrections for ½ credit
Your test corrections must include (as applicable)
The letter of the correct answer and an explanation
A correctly solved problem and an explanation
A correct identification of significant figures or scientific notation and an explanation.
These are due WEDNESDAY, no exceptions.

16. The History of the Atom
Democritus proposed the idea that if you cut a stone into smaller and smaller pieces, at some point you would reach a piece so tiny it could no longer be divided.
Atom from the Greek words
a- “not”
tomos- “to cut”

17. Dalton’s Atomic Theory
Proposed by a professor, John Dalton, in 1803.
It summarized the results of his experiments and those of others.
It combined ideas of elements with that of atoms.

18. Dalton’s Atomic Theory
1. All Matter is made of indivisible and indestructible atoms.

19. Dalton’s Atomic Theory
2. All atoms of a given element are identical in their physical and chemical properties.

20. Dalton’s Atomic Theory
3. Atoms of different elements differ in their physical and chemical properties.

21. Dalton’s Atomic Theory
4. Atoms of different elements combine in simple whole-number ratios to form compounds.

22. Dalton’s Atomic Theory
5. Chemical reactions consist of the combination, separation, or rearrangement of atoms.

23. Concept Check
Match the following statements to one of Dalton’s five points:

24. Concept Check
Zinc is a softer metal than iron, and it reacts more readily with acid than iron does.
Answer:
3. Atoms of different elements differ in their physical and chemical properties.

25. Concept Check
There is no difference between copper found in an ancient Mayan necklace and copper wire freshly made from copper ore.
Answer:
2. All atoms of a given element are identical in their physical and chemical properties.

26. Concept Check
When methane, CH4, burns, it combines with oxygen, O2, in the air to form molecules of water, H2O, and carbon dioxide CO2.
Answer:
5. Chemical reactions consist of the combination, separation, or rearrangement of atoms.

27. Concept Check
The formula for ordinary ethanol is C2H6O, and the formula for acetic acid in vinegar is C2H4O2.
Answer:
4. Atoms of different elements combine in simple whole-number ratios to form compounds.

28. Concept Check
Matter can never really be thrown away. That is one reason that recycling is important.
Answer:
1. All Matter is made of indivisible and indestructible atoms.