Marcus is taking advanced placement chemistry in high school because he loves science and is fascinated by chemistry experimentation. Wade is taking advanced placement chemistry because his guidance counselor told him he needed to if he intended to apply to a pre-med program at a competitive university. Marcus is motivated by motivation, while Wade is motivated by motivation.

Which statement is a good description of a model? a) models are a description of nature based only on one or two variables. b) models are testable ideas but they are not very to most people. c) models are a description of nature that predicts more accurately than real events. d) models are an approximiation of a real system that omits all but most essential variables in a system.