A ball was swung at constant speed in a horizontal circle on the top of a level lab table. Which of the following was the direction of the
acceleration on the ball?

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.