Basic Concepts - Fundamentals of Chemistry - page 11

Chemistry is the study of the interaction of matter and energy and
the changes that matter undergoes. (In nuclear reactions, tiny quantities of
matter are actually converted to relatively large quantities of energy. See
Chapter 21.)

Snapshot Review

❒ Matter has mass and occupies space.

❒ Mass is a measure of the quantity of matter in a sample (but energy

also has a mass equivalent).

A. Which has a greater mass—an automobile or a sewing thimble?

1.4 Chemical Symbols

Because the elements are the building blocks of all materials in the universe,
we need an easy way to identify and refer to them. For this purpose, each
chemical element is identified by an internationally used symbol consisting
of one or two letters. The first letter of an element's symbol is always
capitalized. If the symbol has a second letter, it is a lowercase (small) letter.
The symbol is an abbreviation of the element's name, but some symbols
represent names in languages other than English. The 10 elements whose
symbols and names have different first letters are listed in Table 1.4. A list
of the names and symbols of the first 109 elements, along with some other
information, is presented in a table inside the back cover of this topic. In
that table, the elements are alphabetized according to their names, but dupli-
cate entries appear under the initial letter of the symbols for the elements in
Table 1.4.
The most important symbols for beginning students to learn are given in
Figure 1.5. The names of these elements and their symbols must be memorized.
The elements indicated by pink shading should be learned first. Don't bother to
memorize the numbers shown in the boxes with the elements.
Chemists write symbols together in formulas to identify compounds. For
example, the letters CO represent a compound of carbon and oxygen. Be care-
ful to distinguish the formula CO from the symbol Co, which represents the
element cobalt. The capitalization of letters is very important! Formulas are
sometimes written with subscripts to tell the relative proportions of the elements
present. For example, H 2 O represents water, which has two atoms of hydrogen
for every atom of oxygen present. More about formulas will be presented in
Section 5.1.

Table 1.4 Elements Whose
Names and Symbols Begin
with Different Letters

Name Symbol

Antimony Sb

Gold Au

EXAMPLE 1.7

Iron Fe

Lead Pb

Mercury Hg

Which of the elements of Table 1.4 are not among the most important elements
to learn (see Figure 1.5)?

Potassium K

Silver Ag

Sodium Na

Solution

Tin Sn

Tungsten W

Antimony (Sb) and tungsten (W).