Christopher G. Hamaker, Illinois State University, Normal IL © 2008, Prentice Hall

Evolution of Chemistry The Greeks believed in four basic elements: earth, air, fire, and water. All substances were combinations of these four basic elements. Aristotle added a fifth element, called ether, which he believed filled the space. Aristotle’s influence dominated and shaped our understanding for nearly 2000 years. Chapter 1

Modern Chemistry Chemistry is a science that studies the composition of matter and its properties. Image Courtesy: http://teacherspace.swindsor.k12.ct.us/staff/dwhite/StampSite/index.htm

Branches of Chemistry

Chemistry: The Central Science Most other branches of science demand an understanding of basic chemical principles, and chemistry is referred to as the “central science.” Chapter 1

Scientific Investigations Science is the methodical exploration of nature followed by a logical explanation of the observations. Scientific investigation entails: planning an investigation carefully recording observations gathering data analyzing the results Chapter 1

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. Three forms of scientific knowledge – Hypothesis, theory and law. Chapter 1

It is tentative in nature so it may be rejected or modified. Hypothesis: A generalization to be tested by observation, experimentation, or prediction. It is tentative in nature so it may be rejected or modified. In the scientific world, hypothesis is formulated only after hours of observation, days of calculating and studying, and sometimes years of research into the phenomena of interest. Chapter 1

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. Chapter 1

Scientific Method, continued Scientific Theory: a) explains patterns and forces. b)Incorporate knowledge into explanations as to why phenomena occur as they do. c) Do not become law and remain tentative until disproved or revised. Law: a)Higher-order ideas that describe patterns and phenomena that occur in nature. b)Laws state that which exists. c)They are related to observable phenomena which may be measured. Chapter 1

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Learning Chemistry Different people learn chemistry differently. What do you see in the picture? Chapter 1

Problem Solving Connect the dots using only four straight lines. Experiment until you find a solution. Did you have to use 5 straight lines? No matter which dot we start with, we still need 5 lines. Chapter 1

Chemistry, The Central Science Knowledge of chemistry is important to understanding the world around us. Chapter 1

Chapter Summary Scientists use the ……………..to investigate the world around them. Experiments lead to a hypothesis, which may lead to a …………. or a natural ………. Chemistry is a central science with many branches such as ………………………... The impact of chemistry is felt in many aspects of our …………………….. Chapter 1