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C h e m i s t r y 1 2 C h 1 : T h e C h e m i c a l W o r l d P a g e | 1
Getting Started:
Materials: Obtain the materials noted in the syllabus
Tro, Introductory Chemistry, 6e; Chemistry M12 Lab Manual, 2e, Safety Glasses
and Scientific Calculator
How to start: Review your algebra. If the math in Appendix or on the back page of the
syllabus is difficult, consider taking an algebra course before attempting Chemistry 12.
Read, study and work problems often and regularly to keep up. Look over the materials
to see what resources are available. When starting a new Chapter, first read the section
titles found on the first page of the chapter, the Chapter in Review and Key terms found at
the end of the chapter. After you have a general overview of the upcoming material read
the chapter text before lecture and a second time after the material is covered in lecture.
Work out many examples and problems. Notice the answers to selected problems are
found after the Glossary in the back of the textbook. Be curious, imaginative, willing to
do calculations and committed to learning the material.
Why Study Chemistry –Chemistry provides important understanding of our
world/universe and how it works. It is the foundation that provides the basic language
required for many other science and technological fields. You will learn connections
between the behavior of matter and the particles that are in matter. While some chemicals
are poisonous, many are ordinary such as air and water.
C h e m i s t r y 1 2 C h 1 : T h e C h e m i c a l W o r l d P a g e | 2
Chapter 1: The Chemical World Homework:
Read Chapter 1: Work out sample/practice exercises.
Look over the lab assignment before attending the labs
Begin to Memorize the names (correct spelling) and symbols (capitalize only the
first letter) of the 44 common elements in the handout.
Register for and start the homework online through MasteringChemistry
Chemistry: The science that seeks to understand what matter does by studying what the
very tiny atoms and molecules do. Chemistry is the study of the composition, properties,
and transformations of matter.
Matter: Anything that has mass and occupies space.
Atoms and Molecules: Matter, composition, structure, element, atom, molecule,
compound; chemical bonds. All things are made of atoms.
This image
shows the
Kanji for
“atom”
written with
individual
Fe atoms on
top of Cu
Classifications of Matter:
1. States of Matter- gas, liquid, solid.
Properties (shape, volume, energy content, endothermic, exothermic, phase
changes)
2. Pure Substances- elements (memorize common elements and symbols), molecules,
compounds
3. Mixtures- Heterogeneous, homogeneous (solutions)
Properties of Matter:
Properties: physical, chemical
1. Physical: changes of state, separation of mixtures (filtration, evaporation,
distillation, chromatography)
2. Chemical: Elements to compounds, reactants forming a different compound,
change in chemical structure and composition.
C h e m i s t r y 1 2 C h 1 : T h e C h e m i c a l W o r l d P a g e | 3
The Scientific Method: A systematic procedure for solving problems and exploring
natural phenomena. Chemists employ the scientific method, which makes use of
observations, hypotheses, laws, theories, and experiments.
Observations (data; a series of measurements or observations)
o observations are the foundation of the scientific method
o Some observations are made with the naked eye, while others rely on
instrumentation.
o data can be qualitative descriptions or quantitative measurements.
o Scientific data may be graphed to see relationships.
o data is most useful when collected under controlled conditions, experiments
Hypotheses
o tentative explanations to interpret the observations
o a useful hypothesis must be testable
o must be rejected or corrected when they conflict with experiment
Experiments
o experiments must be repeatable and reproducible
Practical use of the Scientific Method…
Observation/Problem:
The lamp in the bedroom will not light/turn on.
Possible hypotheses:
Come up with some testable hypothesis from your experience
Experiments:
From each hypothesis, an experiment can be conducted to test the
hypothesis/explanation. More observations are obtained through experiments
and over time, a good hypothesis/explanation is repeatable and reproducible.
The cycle of the scientific method is repeated many times with rejections, alterations and
improvements. Numerous observations and experiments lead to Natural Laws and
Theories.
Natural laws (come from observations)
o compactly summarize the results of a large number of observations
o may apply only under special conditions
o are descriptions of nature that predict future outcomes, not explanations
A few examples of Natural Laws(also known as Scientific Laws or just Laws)…
Newton’s Laws of Motion, Dalton’s Law of Partial Pressures, Lavoisier’s Law
of Conservation of Mass
C h e m i s t r y 1 2 C h 1 : T h e C h e m i c a l W o r l d P a g e | 4
Theories (come from hypotheses)
o Are well-tested models that explain and give the underlying causes for
observations and laws.
o Discarded or refined when they can't explain new experimental results
o A good theory...
explains currently available data
is as simple as possible (but no simpler!)
accurately predicts results of future experiments
suggests new lines of work and new ways to think
clearly shows underlying connections
A few examples of Theories…
Heliocentrism (1543, Copernicus), Evolution (1859, Darwin),
Quantum Theory (Max Planck, Einstein, Niels Bohr, Werner Heisenberg, Erwin
Schrödinger, Max Born, Paul Dirac, 1900–1926)
The Scientific Method Quiz
1. A number of people become ill after eating dinner in a restaurant. Which of the
following statements is a hypothesis?
a) The cooks felt really bad about it.
b) Bacteria in the oysters may have caused the illness.
c) Everyone who ate oysters got sick.
d) Symptoms include nausea and dizziness
e) People got sick whether the oysters were raw or cooked.
2. Which of the following statements is a law?
a) Higher altitude means lower boiling points for water, all other things held equal.
b) An egg cooked for 27 minutes in Moorpark was badly overcooked.
c) An egg cooks in 17 minutes at sea level.
d) An egg takes less time to cook in Moorpark than in Denver.
3. Classify each as an observation (O), a natural law (L), or a theory (T)
_____ a) Matter is made of atoms
_____ b) Matter is conserved in chemical reactions
_____ c) When wood burns in a closed container; its total mass does not change
_____ d) A body in motion stays in motion unless acted on by a force
_____ e) The universe began as a cosmic explosion called the Big Bang
_____ f) A stone dropped from 450 meters falls to the ground in 9.6 seconds.
C h e m i s t r y 1 2 C h 1 : T h e C h e m i c a l W o r l d P a g e | 5
Element: A fundamental substance that cannot be chemically changed or broken down
into anything simpler.
About 90 are naturally occurring. 75% of the observed mass of the universe is H
Percentage of Elements by Mass in the Earth
Percentage of Elements by Mass in the Human Body
Memorize the names (correct spelling) and symbols (capitalize only the first letter) of the
44 common elements in the handout.