BCC -iron with a concentration of carbon initially being 0.1 wt.% throughout is packed in carbon black and then placed in a furnace at 900°C. This effectively makes the concentration of carbon 100 wt.% at the surface. How much time will it take (in seconds) for the concentration of carbon to reach 5 wt.% at 1 mm from the surface of the steel? The diffusion coefficient for carbon in BCC -iron at 900°C is 1.4 x 10-10 m²/s

Identify which properties could correspond to solids, plasmas, or both. maintain a unique shape. collide infrequently with other particles. have very high velocities. conduct electricity. protons. have a low temperature. has long-range order.

Which of the following warnings would an agricultural chemist tell a farmer who wants to recycle his or her own ammonia? recycling ammonia is a difficult process that sometimes takes weeks. recycling ammonia requires a degree in biochemistry or a related field. recycling ammonia can be harmful because it is highly flammable and toxic. recycling ammonia costs too much money considering the price of the necessary chemicals.

The bohr model of the atom explained why emission spectra are discrete. it could also be used to explain the photoelectric effect. which is a correct explanation of the photoelectric effect according to the model?