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Chapter 1
Living in a World of Chemistry
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 scienceChemistry 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
8
Scientific MethodHypothesis The initial ,tentative proposal of a scientific principle.
Experiment:Experiments are then designed to test the hypothesisIf the experimental data supports the initial proposal, the hypothesis may lead to a scientific theory.
Scientific Methodscientific theory.An explanation that is based on observation, experimentation & reasoning and has been tested several times.
scientific LawA measurable relationship that summarizes the natural behavior.
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Scientific MethodExample 1A scientific hypothesis is
a) absolute.b) complex.c) simple.d) Tentative
Scientific Method
Example 2What 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.
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Scientific MethodExample 3
A brief statement summarizing many observations of a physical phenomenon is called a
a) scientific theory. b) hypothesis. c) fact. d) scientific law
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 1962.
• She proposed that the use of chemicals to control insects was threatening the destruction of all life.
Ozone Layer
Ozone hole & CFC’S
Ozone hole & CFC’S
Ozone hole & CFC’S
Ozone hole & CFC’S
Ozone hole & CFC’S
Ozone hole & CFC’S
Global Warming
Global Warming• Scientists have measured an average 0.6 °C rise in
atmospheric temperature since 1860
• During the same period atmospheric CO2 levels have risen 25%
• Are the two trends causal?
23
Green House
The Sources of Increased CO2• One source of CO2 is the combustion reactions of fossil fuels
we use to get energy• Another source of CO2 is volcanic action• How can we judge whether global warming is natural or due
to our use of fossil fuels?
25Tro: 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 = BenefitsRisks
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
DNA: Double Helix
ExampleWatson 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?