INTRODUCTORY CHEMISTRYINTRODUCTORY CHEMISTRYConcepts and Critical Thinking
Sixth Edition by Charles H. Corwin
Chapter 1 1© 2011 Pearson Education, Inc.
Chapter 1Introduction to
Chemistryby Christopher Hamaker
Chapter 1 2© 2011 Pearson Education, Inc.
Evolution of Chemistry
• The Greeks believed in four basic elements:
1. Earth
2. Air
3. Fire
4. Water
• All substances were combinations of these four basic elements.
Chapter 1 3© 2011 Pearson Education, Inc.
Scientific Investigations
• Science is the methodical exploration of nature followed by a logical explanation of the observations.
• Scientific investigation entails the following activities:– Planning an investigation– Carefully recording observations– Gathering data
– Analyzing the results
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The Scientific Method
• The scientific method is a systematic investigation of nature and requires proposing an explanation for the results of an experiment in the form of a general principle.
• The initial, tentative proposal of a scientific principle is called a hypothesis.
• After further investigation, the original hypothesis may be rejected, revised, or elevated to the status of a scientific principle.
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Applying the Scientific Method
Step 1: Perform a planned experiment, make observations, and record data.
Step 2: Analyze the data and propose a tentative hypothesis to explain the experimental observations.
Step 3: Conduct additional experiments to test the hypothesis. If the evidence supports the initial proposal, the hypothesis may become a theory.
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Applying the Scientific Method, Continued
• After sufficient evidence, a hypothesis becomes a scientific theory.
• A natural law is a measurable relationship.
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Critical Thinking: Reactions with Oxygen
What do burning wood, rusting iron, and exploding gasoline have in common?
• All three are examples of combustion.
• Combustion is a chemical reaction of a substance with oxygen.
• Rusting is a slow reaction, burning is a rapid reaction, and an explosion is an instantaneous reaction.
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Modern Chemistry
• Chemistry is a science that studies the composition of matter and its properties.
• Chemistry is divided into several branches:– Organic chemistry is the study of substances
containing carbon.
– Inorganic chemistry is the study of all other substances that don’t contain carbon.
– Biochemistry is the study of substances derived from plants and animals.
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Learning Chemistry
• Different people learn chemistry differently.
• What do you see in the picture?
• Some people see a vase on a dark background; some people see two faces.
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Problem Solving
• Connect the dots using only four straight lines.
• Experiment until you find a solution.
• Did you have to use five straight lines?
• No matter which dot we start with, we still need five lines.
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Problem Solving, Continued
• Are we confining the problem?
• We need to go beyond the nine dots to answer the problem.
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Chemistry: The Central Science
• Knowledge of chemistry is important to understanding the world around us.
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Chapter Summary
• Scientists use the scientific method to investigate the world around them.
• Experiments lead to a hypothesis, which may lead to a scientific theory or a natural law.
• Chemistry is a central science with many branches.
• The impact of chemistry is felt in many aspects of our daily lives.