chapter 1: an introduction to chemistry turning on the light © 2003 john wiley and sons publishers...
TRANSCRIPT
Chapter 1: An Introduction to Chemistry
Turning on the Light
© 2003 John Wiley and Sons Publishers
Stone/Getty Images
http://www.youtube.com/watch?v=465RXSHMwsE
How does a battery works
Figure 1.3: An electric light bulb.
© 2003 John Wiley and Sons Publishers
Courtesy Ken Karp
Figure 1.5: The effect of sucrose and of sodium chloride on water’s ability to conduct an electric current.
© 2003 John Wiley and Sons Publishers
How does Table Salt causes Conduction of Electricity?
Figure 1.1: The electrical circuit of a flashlight.
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Figure 1.2: The electrical conductivity of tap water, sugar water, and salt water.
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Electrolytes Produce positive (+) and negative (-) ions
when they dissolve in water. In water conduct an electric current.
Electrolytes
• Strong electrolytes ionize 100% in solution.• Equations for the dissociation of strong
electrolytes show the formation of ions in aqueous (aq) solutions.
H2O 100% ions
NaCl(s) Na+(aq) + Cl-(aq)
Strong Electrolytes
Nonelectrolytes Form only
molecules in water. Do not produce ions
in water. Do not conduct an
electric current.
Nonelectrolytes
The Scientific Method
Observation and Experiments
Patterns & Trends
Formulate & Tests Hypothesis
Theory
Laws
An element is a substance that consist of the same atoms.
• 115 elements have been identified
• 83 elements occur naturally on Earth
gold, aluminum, lead, oxygen, carbon
Universe:H(91%);He(8.75%);Others(0.25%)
• Many elements have been created by scientists
technetium, americium, seaborgium
1.4
Elements mercury, copper, and carbon.
© 2003 John Wiley and Sons Publishers
Courtesy Ken Karp
Figure 2.3: Distribution of the elements in the universe.
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Figure 2.4: Distribution of the elements in the human body.
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Figure 2.5: Composition of the human body.
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• Carbon, oxygen, and hydrogen are the most abundant elements in the human body.
Elements in the Bodyhttp://www.youtube.com/watch?v=im8tmwTnnhM
Names of Elements
• http://www.youtube.com/watch?v=zUDDiWtFtEM
• http://www.hobart.k12.in.us/ksms/PeriodicTable/abc.htm
• http://www.youtube.com/watch?v=Apr7MdbHGQo
Select the correct symbol for each:A. Calcium
1) C 2) Ca 3) CA
B. Sulfur 1) S 2) Sl 3) Su
C. Iron 1) Ir 2) FE 3) Fe
Learning Check
Select the correct symbol for each:
A. Calcium
2) Ca
B. Sulfur
1) S
C. Iron
3) Fe
Solution
Select the correct name for each symbol:A. N
1) neon 2) nitrogen 3) nickel
B. P 1) potassium 2) phogiston 3) phosphorus
C. Ag 1) silver 2) agean 3) gold
Learning Check
Select the correct name for each:
A. N
2) nitrogen B. P
3) phosphorus
C. Ag
1) silver
Solution
What Happens if we pass electricity through water?
When was the last time you did Electrolysis?
What are Compounds?
• Substances composed of two or more elements in a fixed ratio.
H2O( Water)
NaCl (Table Salt),
C12H22O11 (sugar)
Compounds and Mixtures 02
Sodium chloride, hydrogen peroxide, water, and sucrose are some of the more common compounds of our everyday world.
© 2003 John Wiley and Sons Publishers
Courtesy Ken Karp
© 2003 John Wiley and Sons Publishers
What do you think would be the result of placing the wires into a solution made up of a mixture of equal parts of sucrose and sodium chloride?
QUESTION
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Would you expect to find many ions in pure water? Explain.
QUESTION
© 2003 John Wiley and Sons Publishers
How would you go about determining whether an aspirin tablet contains any electrolytes among its ingredients?
QUESTION