Chapter 1: An Introduction to Chemistry

Turning on the Light

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Stone/Getty Images

http://www.youtube.com/watch?v=465RXSHMwsE

How does a battery works

Figure 1.3: An electric light bulb.

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Courtesy Ken Karp

Figure 1.5: The effect of sucrose and of sodium chloride on water’s ability to conduct an electric current.

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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.

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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

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How would you go about determining whether an aspirin tablet contains any electrolytes among its ingredients?

QUESTION