Chapter 1 Introduction to Chemistry by Christopher Hamaker © 2011 Pearson Education, Inc. Chapter 1

Evolution of Chemistry The Greeks believed in four basic elements: 1. Earth Air Fire Water All substances were combinations of these four basic elements. © 2011 Pearson Education, Inc. Chapter 1

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 © 2011 Pearson Education, Inc. 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. 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. © 2011 Pearson Education, Inc. 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. If the evidence supports the initial proposal, the hypothesis may become a theory. © 2011 Pearson Education, Inc. Chapter 1

Applying the Scientific Method, Continued After sufficient evidence, a hypothesis becomes a scientific theory. A natural law is a measurable relationship. © 2011 Pearson Education, Inc. Chapter 1

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. © 2011 Pearson Education, Inc. Chapter 1

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. © 2011 Pearson Education, Inc. Chapter 1

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. © 2011 Pearson Education, Inc. Chapter 1

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. © 2011 Pearson Education, Inc. Chapter 1

Problem Solving, Continued Are we confining the problem? We need to go beyond the nine dots to answer the problem. © 2011 Pearson Education, Inc. Chapter 1

Chemistry: The Central Science Knowledge of chemistry is important to understanding the world around us. © 2011 Pearson Education, Inc. Chapter 1

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. © 2011 Pearson Education, Inc. Chapter 1

World of Chemistry

The Language of Chemistry CHEMICAL _____________ - pure substances that cannot be decomposed by ordinary means to other substances. Aluminum Bromine Sodium

The Language of Chemistry The elements, their names, and symbols are given on the PERIODIC TABLE How many elements are there? 117 elements have been identified 82 elements occur naturally on Earth Examples: gold, aluminum, lead, oxygen, carbon 35 elements have been created by scientists Examples: technetium, americium, seaborgium

The Periodic Table Dmitri Mendeleev (1834 - 1907)

Glenn Seaborg (1912-1999) Discovered 8 new elements. Only living person for whom an element was named.

Branches of Chemistry Many major areas of study for specialization Several career opportunities Also used in many other jobs

1. Organic Chemistry Organic is the study of matter that contains carbon Organic chemists study the structure, function, synthesis, and identity of carbon compounds Useful in petroleum industry, pharmaceuticals, polymers

2. Inorganic Chemistry Inorganic is the study of matter that does NOT contain carbon Inorganic chemists study the structure, function, synthesis, and identity of non-carbon compounds Polymers, Metallurgy

3. Biochemistry Biochemistry is the study of chemistry in living things Cross between biology and chemistry Pharmaceuticals and genetics

4. Physical Chemistry Physical chemistry is the physics of chemistry… the forces of matter Much of p-chem is computational Develop theoretical ideas for new compounds

5. Analytical Chemistry Analytical chemistry is the study of high precision measurement Find composition and identity of chemicals Forensics, quality control, medical tests

Types of Observations and Measurements We make QUALITATIVE observations of reactions — changes in color and physical state. We also make QUANTITATIVE MEASUREMENTS, which involve numbers. Use SI units — based on the metric system