1. A periodic disturbance that transfers energy through a medium or empty space is called? Answer ASAP

Ahypothesis is? close agreement by competent observers of observations of the same phenomena. a guess that has been tested over and over again and always found to be true. an educated guess that has yet to be proven by experiment. the long side of a right triangle. a synthesis of a large collection of information that includes guesses.

Heterogeneous mixture with larger particles that never settle is

Which system of units is used by only a small number of countries in the world, including the u.s.