Uranium is: Select one:
a. a naturally occurring material found in
numerous minerals
b. a waste by-product of nuclear reactors
C. created in special nuclear reeactors
d. artificially produced in nuclear
reactors
PNS
e. created in a special particle
accelerator​

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.