Sound waves require a medium to travel through, such as a solid, liquid or gas because a) waves cannot move through a vacuum b) sound only works within certain pressures c) waves only work within certain tempuratures d) sound is molecules bumping into one another

they are non-matter

explanation:

they are non-matter. basically, any type of energy or any abstract concept is an example of something that does not matter. other examples include dreams, magnetism, radio, and hate

energy can be converted from one form to another, but it cannot be created or destroyed in ordinary chemical or physical means. do not understand what you are asking but hope this