Chapter 1 Introduction to Lecture Presentation Chapter 1 Introduction to Chemistry John Singer Jackson College
Evolution of Chemistry The Greeks believed in four basic elements: Air Fire Water Earth All substances were combinations of these four basic elements.
The Scientific Method Science is the methodical exploration of nature followed by a logical explanation of the observations.
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 Scientific Method The initial, tentative proposal of a scientific principle is called a hypothesis.
The Scientific Method An experiment involves exploring nature and testing hypotheses according to a planned strategy to make observations under controlled conditions. Realize that a hypothesis is testable. An experiment is a test.
Distinction between Theory and Law The Scientific Method Distinction between Theory and Law A theory is a model that explains the behavior of nature. A natural law does not explain behavior but rather states a measurable relationship. In other words, a law describes nature. A theory explains.
Distinction between Theory and Law The Scientific Method Distinction between Theory and Law Keep in mind that a law is a “what” and a theory is a “why.” Also realize that “whats” never become “whys” no matter how good they are.
Applying the Scientific Method A natural law states a measurable relationship.
Modern Chemistry Chemistry is a science that studies the composition of matter and its properties.
Chemistry is divided into several branches: Modern Chemistry 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. Green chemistry is the design of chemical processes that reduce waste and hazardous substances.
Chemistry Connection: “Worth Your Salt?” Salt was once so valuable, it was used to pay Roman soldiers. Table salt is obtained by three major processes: Salt mining Solution mining Solar evaporation of salt water Table salt is necessary for the human body, but too much can cause high blood pressure.
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.
Problem Solving Connect the dots using only four straight lines. Experiment until you find a solution.
Problem Solving Did you have to use five straight lines? No matter which dot we start with, we still need five lines.
Problem Solving Are we confining the problem? We need to go beyond the nine dots to answer the problem.
Chemistry: The Central Science Knowledge of chemistry is important to understanding the world around us.
Chemistry Connection: A Student Success In 1886, pure aluminum metal cost over $100,000 per pound. Charles Hall and Paul Hèroult both independently discovered a method for obtaining pure aluminum from aluminum ore. The industrial process for obtaining aluminum metal is referred to as the Hall–Hèroult process. Today, pure aluminum costs less than $1 per pound.
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.