Chemistry Reference
In-Depth Information
grass (see Chapter 7). Other heterogeneous materials are
wood
and
bone
,
both examples of living forms of heterogeneous matter.
Wood
is a mixture
of three organic substances - namely, cellulose, hemicellulose, and lignin
(see Chapter 9);
bone
is an interspersed mixture of
collagen
, an organic
substance, and
carbonated hydroxyapatite
, a bioinorganic substance
(see Chapter 15). Heterogenous materials can be separated into their
homogeneous components using physical techniques (see Fig. 1).
FIGURE 1
Classification of matter.
Matter, everything that has mass and takes
up space, is made up of very small particles known as “atoms.” Particular kinds
of matter that have uniform composition and properties throughout are known
as “substances.” Substances may occur alone (separate from) or mixed with other
substances. Gold and lime, for example, often occur separate from others in
nature: gold as gold nuggets and lime as limestone rocks. Mixtures of two or
more substances may be homogeneous or heterogenous; seawater, wine,
fruitjuice, and some alloys are homogeneous mixtures, with no visible separa-
tion between their components. Seawater, for example, is a solution (a homo-
geneous mixture) of various salts in water. Granite, brick, pottery, cement, and
wood are heterogeneous mixtures of various substances.
