Why are some materials clear and others opaque?
Sometimes being clear is defined as a quality or purity.
Other times, we need to make a substance clear such as
glass or varnish. Knowing why and in what condition the
material s are clear in can help us achieve the ability of
converting opaque materials to clear materials or vice
versa if needed. We all have seen glasses, plastic, soap,
shampoo, all kinds of food, in clear and not clear
conditions. Now we need to find out how being clear or
opaque is an optical property of a substance.
In order to make an opaque substance clear, you must make
it to one piece of crystal or to totally take away all
crystals. To make a clear substance opaque, you must crush
and make tat substance into powder, which will take away
We start out the experiment by getting a few clear samples
and attempt to make them opaque. For our first test, you
will need either salt or sugar crystals. Take one grain of
either the salt or sugar, and look at it. As you can see,
it is clear and that you can see right through it. Now,
take a spoon full of salt or sugar and put it on the same
surface. As you can see, it is opaque this time and is not
clear, yet it is the same clear grains of crystal. This
shows that crystals are only clear if they are in one
piece. That means that if you break up that one piece into
twenty pieces piled up on top of each other, they will no
longer be clear. In the next experiment, take a clear
crystal and crush it fully. When you are done crushing it,
you will notice that it is a white unclear powder. Even
though every single piece of this powder under a
microscope is clear, the powder that is a group of clear
components is not clear. Next, dissolve the white powder
in water. The crystals become clear again. It stays clear
until the water evaporates and it becomes crystal again.
For our final and last experiment, you will need an ice
cube. Take the ice cube and look at it. It is clear for
the most part. Now crush the ice and you will notice that
it is no longer clear but is opaque.