1.The Venn diagram above compares chemical changes to physical changes. Which does NOT belong at R?A)change in color B)change in density C)change in shape D)change in state of matter

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.