)nitrogen from a gaseous phase is to be diffused into pure iron at 700°c. if the surface concentration is maintained at 0.12 wt% n, what will be the concentration (in weight percent) 4.5 mm from the surface after 8.0 h? the diffusion coefficient for nitrogen in iron at 700°c is 4.6 × 10-10 m2/s.

Select the correct answer. why are scientific models important in the study of science? a. they always involve critical mathematical calculations. b. they scientists understand complex ideas and objects that aren’t easy to handle. c. they enable scientists to popularize their work in society. d. they are required when conducting any peer review process. e. they are necessary for turning a hypothesis into a law.