The noise that the plane makes is sometimes so loud that you cannot hear any other noise. Sound is a type of energy. Sounds are produced when an object vibrates. When this happens, the air around the object also vibrates. These vibrations in the air travel as sound waves. A jet engine makes a great deal of sound energy. The engine sounds loud when it is close, but you can sometimes hear the noise when the plane is even several miles away from you.
Definition of Polymer. A large molecule consisting of chains or rings of linked monomer units, usually characterized by high melting and boiling points.
Monomers are the basic molecular form in which polymers and plastics are produced. Polymers consist of repeating molecular units, which usually are joined by covalent bonds. For a molecule to be a monomer, it must be at least bifunctional insofar as it has the capacity to interlink with other monomer molecules.