INTRODUCTION TO GENERAL, ORGANIC, AND BIOCHEMISTRY
MATTER, ENERGY, AND MEASUREMENT
1.1 WHY DO WE CALL CHEMISTRY THE STUDY OF MATTER?
The world around us is made of chemicals. Our food, our clothing, the buildings
in which we live are all made of chemicals. Our bodies are made of chemicals, too. To
understand the human body, its diseases, and its cures, we must know all we can about
those chemicals.
HOW HAS THIS MEDICAL PROGRESS COME ABOUT?
The answer is that diseases could not be cured until they were understood, and this
understanding has emerged through greater knowledge of how the body functions.
THE UNIVERSE CONSISTS OF MATTER, ENERGY, AND EMPTY SPACE.
Matter - is anything that has mass and takes up space.
- It has long been known that matter can change, or be made to change, from
one form to another.
chemical change, more commonly called a chemical reaction, substances are
used up (disappear) and others are formed to take their places.
Chemical properties - the chemical reactions that it undergoes.
Physical properties - properties that do not involve chemical reactions.
Example: density, color, melting point, and physical state (liquid, solid, gas)
(a) (b) (c)
, A CHEMICAL REACTION
(a) Bromine, an orange-brown liquid, and aluminum metal.
(b) These two substances react so vigorously that the aluminum becomes molten and
glows white hot at the bottom of the beaker. The yellow vapor consists of vaporized
bromine and some of the product of the reaction, white aluminum bromide.
(c) Once the reaction is complete, the beaker is coated with aluminum bromide and
the products of its reaction with atmospheric moisture
Chemistry is the science that deals with matter: the structure and properties of matter
and the transformations from one form of matter to another.
1.2 WHAT IS THE SCIENTIFIC METHOD?
SCIENTIFIC METHOD - Scientists learn by using a tool.
The heart of the scientific method is the testing of theories.
FACT - is a statement based on direct experience. It is a consistent and
reproducible observation. Having observed this fact, Galen then proposed a
hypothesis to explain it.
HYPOTHESIS - is a statement that is proposed, without actual proof, to explain
the facts and their relationship.
THEORY - is the formulation of an apparent relationship among certain observed
phenomena, which has been verified to some extent.
1.3 HOW DO SCIENTISTS REPORT NUMBERS?
Scientists often have to deal with numbers that are very large or very small. For
example, an ordinary copper penny (dating from before 1982, when pennies in the
United States were still made of copper) contains approximately
29,500,000,000,000,000,000,000 atoms of copper and a single copper atom weighs
0.00000000000000000000000023 pound
which is equal to
0.000000000000000000000104 gram
Many years ago, an easy way to handle such large and small numbers was devised.
This method, which is called exponential notation, is based on powers of 10. In
exponential notation, the number of copper atoms in a penny is written
MATTER, ENERGY, AND MEASUREMENT
1.1 WHY DO WE CALL CHEMISTRY THE STUDY OF MATTER?
The world around us is made of chemicals. Our food, our clothing, the buildings
in which we live are all made of chemicals. Our bodies are made of chemicals, too. To
understand the human body, its diseases, and its cures, we must know all we can about
those chemicals.
HOW HAS THIS MEDICAL PROGRESS COME ABOUT?
The answer is that diseases could not be cured until they were understood, and this
understanding has emerged through greater knowledge of how the body functions.
THE UNIVERSE CONSISTS OF MATTER, ENERGY, AND EMPTY SPACE.
Matter - is anything that has mass and takes up space.
- It has long been known that matter can change, or be made to change, from
one form to another.
chemical change, more commonly called a chemical reaction, substances are
used up (disappear) and others are formed to take their places.
Chemical properties - the chemical reactions that it undergoes.
Physical properties - properties that do not involve chemical reactions.
Example: density, color, melting point, and physical state (liquid, solid, gas)
(a) (b) (c)
, A CHEMICAL REACTION
(a) Bromine, an orange-brown liquid, and aluminum metal.
(b) These two substances react so vigorously that the aluminum becomes molten and
glows white hot at the bottom of the beaker. The yellow vapor consists of vaporized
bromine and some of the product of the reaction, white aluminum bromide.
(c) Once the reaction is complete, the beaker is coated with aluminum bromide and
the products of its reaction with atmospheric moisture
Chemistry is the science that deals with matter: the structure and properties of matter
and the transformations from one form of matter to another.
1.2 WHAT IS THE SCIENTIFIC METHOD?
SCIENTIFIC METHOD - Scientists learn by using a tool.
The heart of the scientific method is the testing of theories.
FACT - is a statement based on direct experience. It is a consistent and
reproducible observation. Having observed this fact, Galen then proposed a
hypothesis to explain it.
HYPOTHESIS - is a statement that is proposed, without actual proof, to explain
the facts and their relationship.
THEORY - is the formulation of an apparent relationship among certain observed
phenomena, which has been verified to some extent.
1.3 HOW DO SCIENTISTS REPORT NUMBERS?
Scientists often have to deal with numbers that are very large or very small. For
example, an ordinary copper penny (dating from before 1982, when pennies in the
United States were still made of copper) contains approximately
29,500,000,000,000,000,000,000 atoms of copper and a single copper atom weighs
0.00000000000000000000000023 pound
which is equal to
0.000000000000000000000104 gram
Many years ago, an easy way to handle such large and small numbers was devised.
This method, which is called exponential notation, is based on powers of 10. In
exponential notation, the number of copper atoms in a penny is written
