We measure the rate at which distance is traveled during an instant of time. Which is this rate? A. displacement
B. average velocity
C. instantaneous speed
D. average speed

Which statement is the best definition of an atom? a) anything that has mass and occupies space. b) the smallest particle that has the properties of an element. c) a substance that cannot be broken down chemically into simpler substances. eliminate d) the smallest unit of a substance that exhibits all of the properties characteristic of that substance.