Fundamentals of Chemistry
DOE-HDBK-1015/1-93
CHARACTERISTICS OF ATOMS
Rev. 0
CH-01
Page 1
CHARACTERISTICS OF ATOMS
Chemistry is defined as the systematic investigation of the properties,
structure, and behavior of matter and the changes matter undergoes. This
general definition raises many questions. These questions are answered in
the study of chemistry. Terms and basic concepts that help in understanding
chemistry will be discussed in this chapter.
EO 1.1
DEFINE the following terms:
a.
States of matter
d.
Mole
b.
Atomic weight
e.
Gram atomic weight
c.
Molecular weight
f.
Gram molecular weight
EO 1.2
LIST the components of an atom, their relative sizes, and
charges.
EO 1.3
STATE the criterion used to classify an atom chemically.
Characteristics of Matter
The term states of matter refers to the physical forms in which matter exists: solid, liquid, and
gas. Solids are characterized as having both a definite shape and a definite volume. In a solid,
the forces that keep the molecules or atoms together are strong. Therefore, a solid does not
require outside support to maintain its shape.
Liquids have definite volumes but indefinite shapes and are slightly compressible. Liquids take
the shape of their containers. The forces that keep a liquid's molecules or atoms together are
weaker than in the solids.
Gases are readily compressible and capable of infinite expansion. They have indefinite shape and
indefinite volume. Of the three states, gases have the weakest forces holding their molecules or
atoms together.
The different states of matter have one thing in common; they can all be broken down into
fundamental units called atoms.
