Chemical
Substances:
The
Building
Blocks
of
Life Chemical
substances
are
the
basic
building
blocks
of
life.
From
the
air
we
breathe
to
the
food
we
eat,
everything
around
us
is
composed
of
different
types
of
chemicals.
These
substances
are
integral
to
our
survival
and
are
used
in
various
industries
from
medicine
to
agriculture. One
of
the
most
well-known
chemical
substances
is
water
(H2O).
It
is
essential
for
all
living
beings
as
it
is
required
for
various
physiological
processes
such
as
digestion
and
circulation.
In
fact,
the
human
body
is
composed
of
about
60%
water.
However,
water
is
not
the
only
essential
chemical
in
our
lives.
Oxygen
(O2)
is
necessary
for
respiration,
while
carbon
dioxide
(CO2)
is
produced
as
a
by-product
of
respiration
and
is
necessary
for
plant
growth. Chemical
substances
are
also
used
in
various
industries.
For
example,
sodium
chloride
(NaCl)
is
commonly
known
as
table
salt
and
is
used
in
cooking
and
food
preservation.
Calcium
carbonate
(CaCO3)
is
used
in
the
construction
industry,
while
ammonium
nitrate
(NH4NO3)
is
used
in
fertilizer
p「了解更多 生肖配对常识请关注 :99星座知识网,wWw.alM99.COm〕roduction. However,
some
chemical
substances
are
harmful
if
not
handled
properly.
For
example,
lead
(Pb)
and
mercury
(Hg)
are
toxic
metals
that
can
cause
serious
health
problems
if
ingested.
Chlorofluorocarbons
(CFCs),
which
were
once
commonly
used
in
refrigeration
and
air
conditioning,
were
found
to
harm
the
ozone
layer
and
are
now
banned
in
many
countries. In
conclusion,
chemical
substances
are
an
integral
part
of
our
lives,
used
in
everything
from
the
air
we
breathe
to
the
food
we
eat.
While
some
chemicals
are
essential
for
life,
others
can
be
harmful
if
not
handled
correctly.
It
is
important
to
understand
the
properties
of
chemical
substances
and
their
potential
effects
on
the
environment
and
human
health.