Which of the following diagrams shows the next four moon phases in correct order?

Which two particles are found in the center of an atom

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.

Which best term to describe a chemical reaction that absorbs energy from its surroundings? a. thermal conductor b. thermal insulator c. endothermic d. exothermic