Space gives rise to quarks which form atoms that
join together to compose all of the organic and inorganic molecules
of the material universe.
A molecule is the smallest particle any compound material
can be divided into without changing into a different material.
A molecule is the next order of magnitude greater than the atom,
and serves as one of the common building units of our world.
The structure of a molecule depends on the arrangement of its atoms,
as well as on their kinds and numbers. For example, two different
kinds of molecules may be formed depending on whether a particular
atom is beside or between two other atoms.
The size and weight of a molecule varies according to the atoms
which comprise it. A water molecule, for example, contains two light
hydrogen atoms and one oxygen atom, and has a diameter of one-hundred-millionth
of an inch. While larger molecules such as lead or uranium contain
Without molecules, there would be no sound, no musical tones, no
Without molecules, there would be no music.
Large numbers of molecules comprise the various media of gas, liquids,
solids, and plasma. Sound travels within these media whenever an
oscillating source causes the normally random molecules to vibrate
forward and backward, producing collisions which cause the propagation
of sound waves through the medium.
In their normal random motion in air, individual molecules travel
at an average speed of around 1000 miles per hour, a third faster
than sound. Sound travels at about 750 miles per hour in air, at
If all molecules were vibrating at the same rate and in the same
direction, sound would travel at exactly molecular speed. But because
individual molecules in a sound wave vibrate in many directions
at different rates, the average speed of sound traveling in a medium
occurs at about 30 percent less than the average random motion of