A diffusion process is run at 1200 ºC with the surface concentration of diffusing atoms kept constant at 1024 atoms/m3 . The process is run for 3 h. If there are no diffusing atoms at the start of the diffusion process inside the diffusing material, at what depth below the surface is the concentration of atoms 1022 atoms/m3 ? The diffusion coefficient at 1200ºC is 7.0 X 10-17 m2 /s.

The picture represents the process that produces most of the energy used by living organisms on earth. which process is represented in the picture? a) the magnetic attraction between two hydrogen nuclei. b) the fusion of hydrogen nuclei to produce a helium nucleus in the core of the sun. c) the fission of hydrogen nuclei to produce a helium nucleus in the core of the sun. d) the chemical reaction between hydrogen nuclei to produce a helium nucleus in earth's atmosphere.