
The
search for the smallest particle of matter led scientists to develop
new observation tools, such as very powerful microscopes. Scientific
observations using these new tools led to the discovery of small paticles
called atoms.
All
matter is made up of these small particles or atoms. Atoms are always
moving, but the movement of one atom is very hard to observe, because
it is so small. Atoms are made up of smaller particles that are also
in motion. Scientists have difficulty observing the actual movement
of the particles that atoms are made of. Therefore, particle movement
is more easily observed by noting changes caused by such motion. For
example, while air cannot be seen, it often can be used to show particle
motion.
Place
an open bottle of perfume at one corner of a room. Get a friend to stand
at the opposite corner of the room and time how long it takes for them
to first smell the perfume. This shows that the perfume particles move
along with the air particles. Now try using different kinds of perfume.
Make a hypothesis prior to testing each brand. Did each kind of perfume
move through the air at the same speed? If one kind moved faster or
slower than the others, what do you think was the cause of the different
speed? Is there a possible relationship between the kinds of perfumes
you tested and the speed they moved through the room? Now design an
experiment to test your hypothesis about how fast these particles move.