If aluminum is diffused into a thick slice of silicon with no previous aluminum in it at a temperature of 1100oC for 303 minutes, what is the depth below the surface at which the concentration is 1016 atoms/cm3 if the surface concentration is 1018 atoms/cm3? D = 2 x 10-12 cm2/s for aluminum diffusing in silicon at 1100oC. The answer should be in mm with 4 decimals of accuracy.

Darla claims that the first periodic table developed by mendeleev was not completely accurate, so it is not useful at all. harmony argues that it establish the periodic table we use today, making it more credible. who is correct and why? darla is correct, because a model that has any mistakes should be thrown out. darla is correct, because a good model would not need to change. harmony is correct, because mendeleev’s model had all of the information correct in the first version. harmony is correct, because mendeleev’s model made predictions that came true.

Rank the four gases (air, exhaled air, gas produced from from decomposition of h2o2, gas from decomposition of nahco3) in order of increasing concentration of co2

Aweight lifter raises a 1600 n barbell to a height of 2.0 meters. how much work was done? w = fd a) 30 joules b) 3000 joules c) 320 joules d) 3200 joules