Unit 1.1 Defining Chemistry
How does soap relate to chemistry?
Chemistry affects every area of our lives. Here is just
one example of chemistry in action – the making of
soaps. Soap was once made by boiling animal fat in ashes
– the product was hard on the skin and not very pleasant
to use. Today, soap manufacture involves complicated
chemical processes to provide a wide variety of soaps
for different skin types. Colors and odors can be
custom-made for that individual experience.
Defining Chemistry
What is this made of? How can we produce this material quicker and at lower cost? Will this product
harm us or help us? All of these questions can be answered using the science of chemistry.
What is Chemistry?
If we look up the word “chemistry” in the dictionary, we’ll find something like this: “The science of the
composition, structure, properties, and reactions of matter, especially of atomic and molecular
systems” (Free Online Dictionary). Another definition states that "chemistry" is the study of matter
and changes in that matter. These definitions are certainly accurate, but do not give a good picture of
the scope of chemistry or of the many interesting aspects of the field.
Chemistry touches every area of our lives. The medicines we take, the food we eat, the clothes we wear –
all these materials and more are, in some way or another, products of chemistry.
What is the World Made of?
Questions about matter have been asked for centuries. The ancient Greek philosophes spent a lot of
time trying to figure out what matter was. Different philosophers debated whether matter was earth,
water, air, fire, or some combination. They argued, but did not do any experiments at that time.
It took many centuries for humans to develop a better concept of what matter really is. Even today, we
have an incomplete picture of exactly what this stuff is that we can touch and see. Chemistry involves
the study of these substances, both in terms of basic properties and also learning all the things we can
do with matter.
Chemists look at the world in two ways, often simultaneously. The two worlds of the chemist are
the macroscopic world and the microscopic world. Macroscopic refers to substances and objects that
can be seen, touched, and measured directly. Microscopic refers to the small particles that make up all
matter. Chemists must observe matter and do experiments macroscopically and then make
generalizations and propose explanations that are microscopic in nature. For example, anyone can
observe the physical change in appearance that occurs as an iron object such as a tractor that is left out
in the elements gradually turns to rust. However, a chemist looks at the rusting tractor and thinks about
what is going on with the individual atoms that make up the iron and how they are changing as a result of
exposure to oxygen in the air and water from rain. Throughout your study of chemistry, you will often
switch back and forth between the macroscopic and microscopic worlds.
How do guitars vary in both sound and style?
In talking with guitar players, it is not enough to say “I
play the guitar.” The next question is always “Oh, what do
you play?” In the picture above, we see several styles of
guitars. There are two acoustic guitars (non-electric,
non-amplified) and three different electric guitars. Not
shown are instruments such as a classical guitar (six nylon
strings instead of steel strings), a bass guitar (usually
four strings, but some have five), a resonator guitar for
slide blues (uses open tunings), an electric steel guitar
(for country music) and a Hawaiian guitar. Guitar players
specialize in a type of instrument and style of music. The
same is true of chemistry and other sciences.
Areas of Chemistry
The study of modern chemistry has many branches, but can generally be broken down into five main
disciplines, or areas of study:
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physical chemistry
organic chemistry
inorganic chemistry
analytical chemistry
biochemistry
Physical Chemistry is the study of macroscopic properties, atomic properties, and phenomena in
chemical systems. A physical chemist may study such things as the rates of chemical reactions, the
energy transfers that occur in reactions, or the physical structure of materials at the molecular level.
Organic Chemistry is the study of chemicals containing carbon. Carbon is one of the most abundant
elements on Earth and is capable of forming a tremendously vast number of chemicals (over twenty
million so far). Most of the chemicals found in all living organisms are based on carbon.
Inorganic Chemistry is the study of chemicals that do not, in general, contain carbon. Inorganic
chemicals are commonly found in rocks and minerals. One current important area of inorganic chemistry
deals with the design and properties of materials involved in energy and information technology. Our year
will concentrate on Inorganic chemistry.
Analytical Chemistry is the study of the composition of matter. It focuses on separating, identifying,
and quantifying chemicals in samples of matter. An analytical chemist may use complex instruments to
analyze an unknown material in order to determine its various components.
Biochemistry is the study of chemical processes that occur in living things. Research may cover basic
cellular processes up to understanding disease states so better treatments can be developed.
In practice, chemical research is often not limited to just one of the five major disciplines. A particular
chemist may use biochemistry to isolate a particular chemical found in the human body such as
hemoglobin, the oxygen carrying component of red blood cells. He or she may then proceed to analyze
the hemoglobin using methods that would pertain to the areas of physical or analytical chemistry. Many
chemists specialize in areas that are combinations of the main disciplines, such as bioinorganic chemistry
or physical organic chemistry.
Summary
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Chemistry is the study of matter and the changes it undergoes.
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Five areas of chemistry are described:
Chemistry considers both macroscopic and microscopic information.
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physical chemistry
organic chemistry
inorganic chemistry
analytical chemistry
biochemistry
Review
1.
How did ancient philosophers study the world around them?
2.
What is the macroscopic world?
3.
What is the microscopic world?
Match the project with the proper chemistry discipline.
a. measuring mercury in seawater
1. biochemistry
b. studying enzymes in cells
2. organic chemistry
c. measuring the electrical properties of solutions
3. inorganic chemistry
d. synthesizing new carbon compounds
4. physical chemistry
e. making new compounds for energy processes
5. analytical chemistry
Answers:
1. By observation and discussion. No experimentation.
2. Working with objects large enough to see, touch and measure directly.
3. Refers to particles too small to see, yet make up all matter.
Matching:
a. mercury
5. analytical
b. enzymes
1. Biochemistry
c. solutions
3. inorganic
d. carbon cmpd 2. organic
e. energy
4. physical