14. Metals are malleable.
Malleable or
Malleability - metals
ability to be shaped or
formed as by hammering or
pressure; can be beaten
into thin sheets
33. Some metalloids are useful
semiconductors, which are used in
electronics (radio, computers,
telephones, etc.)
They are useful because they
conduct just the right amount of
electricity or heat.
35. Some metals like gold, silver, and platinum
are found as pure substances in the earth’s
crust because they are least reactive.
Most metals are reactive and are found as
oxides (react with oxygen), carbonates
(react with carbon), sulfides (react with
sulfur).
36. Minerals : are elements
or compounds which
occur naturally inside the
earth’s crust.
Ore : is a mineral from
which metals can be
extracted profitably.
38. Ever break the point of
your pencil? That’s
because it’s made of
graphite, a substance
made up completely of
Carbon—a brittle
nonmetal.
Carbon
atoms in
graphite
39. However diamonds, the hardest
material of all, are made of the
same element: Carbon. Look at
how the carbon atoms are
arranged in diamonds—why do
you think diamonds are harder
than graphite?
Editor's Notes
You may also want to discuss how we are using carbon to create new materials such as nanotubes, or discuss buckeyballs.