How can this system be brought to equilibrium? a) add a 5 n force acting in the same direction as the 10 n force. b) add a 10 n force acting in the same direction as the 10 n force. c) add a 10 n force acting in the same direction as the 20 n force. d) add a 20 n force acting in the same direction as the 20 n force.

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.