Chapter 1 Living in a World of Chemistry
Chemistry is the study of matter and changes it undergoes. Everything that we do involves chemistry
Chemistry : a central science Chemistry is a central science. It is involved in all we do.
Chemistry : a central science Science is the process of seeking an understanding of underlying principles of nature. It involves two facets: technological (or factual), and philosophical (or theoretical). Technology is the direct application of knowledge to solve problems. Science grew out of natural philosophy or the philosophical speculation of nature.
Scientific Investigations Science is the systematic 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
The essential steps of Scientific Method are summarized in the next slide
Scientific Method Hypothesis The initial,tentative proposal of a scientific principle. Experiment: Experiments are then designed to test the hypothesis If the experimental data supports the initial proposal, the hypothesis may lead to a scientific theory. 8
Scientific Method scientific theory. An explanation that is based on observation, experimentation & reasoning and has been tested several times. scientific Law A measurable relationship that summarizes the natural behavior.
Scientific Method Example 1 A scientific hypothesis is a) absolute. b) complex. c) simple. d) Tentative 10
Scientific Method Example 2 What is a scientific theory? a)It is a collection of experimental data. b)It is an assertion of scientific fact. c)It is a speculation about the natural phenomena. d)It is an explanation of natural phenomena that has undergone significant testing.
Scientific Method Example 3 A brief statement summarizing many observations of a physical phenomenon is called a a) scientific theory. b) hypothesis. c) fact. d) scientific law 12
Baconian Dream and Carsonian Nightmare It was the dream of Francis Bacon (philosopher) that science would solve the world’s problems and enrich human life with new inventions, thereby increasing happiness and prosperity
Baconian Dream and Carsonian Nightmare Rachel Carson (biologist) published Silent Spring in She proposed that the use of chemicals to control insects was threatening the destruction of all life.
Ozone Layer
Ozone hole & CFC’S
Global Warming
Scientists have measured an average 0.6 °C rise in atmospheric temperature since 1860 During the same period atmospheric CO 2 levels have risen 25% Are the two trends causal? 23
Green House
The Sources of Increased CO 2 One source of CO 2 is the combustion reactions of fossil fuels we use to get energy Another source of CO 2 is volcanic action How can we judge whether global warming is natural or due to our use of fossil fuels? 25 Tro: Chemistry: A Molecular Approach, 2/e
Global Warming & Fossil Fuels
Global Warming & Green house Effect
Risk-benefit analysis Science and technology are interrelated. They involve both risks and benefits. Risk-benefit analysis involves an estimation called the desirability quotient (DQ). DQ = Benefits Risks
Basic & Applied Science Basic research involves the search for knowledge for its own sake. The findings of basic research can someday be applied to a specific problem in industry or the environment.
Basic & Applied Science/Research Applied research involves studying a specific problem in the industry or the environment. George Washington Carver’s work with peanuts was an example of applied research. In doing so, he developed more than 300 products from peanuts.
DNA: Heriditary material DNA analysis has played an important role in ‘Forensic science” Helped understanding heriditary diseases. Helped develop drugs to cure these diseases Developing Gene Therapy
DNA: Double Helix
Example Watson and Crick proposed that DNA exists as a(n) A) alpha helix. B) double helix. C) beta sheet. D) pleated sheet
Your Attitude toward 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. How do you look at chemistry?