Ch. 1: The Chemical World Dr. Namphol Sinkaset Chem 152: Introduction to General Chemistry

I. Chapter Outline I.Introduction II.Atoms and Molecules III.The Scientific Method IV.Succeeding in Chemistry

I. Layman’s View of Chemicals

I. Educated View of Chemicals

I. The Nature of Chemistry Revolves around the question “Why?” Make connections between macroscopic and microscopic behavior.

II. Atoms and Molecules Microscopic view refers to atoms. Atoms can bind together to form molecules. chemistry: the science that seeks to understand what matter does by studying what atoms/molecules do

II. Carbon Dioxide and Water

III. The Scientific Method A way of learning that emphasizes observation and experimentation.

III. It Begins w/ Observations Scientists begin their study by making an observation or measurement. Observation can be simple description or complex measurement. e.g. Fleming noticed bacteria-free rings around a certain mold. e.g. Lavoisier measured masses before and after combustion reactions.

III. A Hypothesis is Formed and Tested Observations lead to preliminary interpretation or explanation. The hypothesis should be falsifiable. Hypotheses are tested via experiments. experiment: highly controlled observations designed to validate/invalidate a hypothesis. Results may lead to revision of hypothesis.

III. Scientific Laws Many similar observations may be developed into a scientific law. scientific law: statement that synthesizes past observations and predicts future ones Laws can be tested with experiments as well.

III. Theories One or more well-established hypotheses can be formulated into a theory. theory: models of nature that provide a broader and deeper explanation of observations and laws A lot of work goes into formulating a theory; they are the height of scientific understanding…not “just a theory.”

IV. Keys to Success Curiosity – you need to be interested in finding out the “why” of things. Math – you need to have the math skills to deal with and calculate quantities in chemistry. Hard work – you need to be able to commit the time and effort to be successful.