A nuclear physicist discovers a new supply of uranium. Calculate the average atomic mass of the sample if the following abundances exist in the new sample: U-238 (0.991), U-235 (0.007) and U-234 (0.002).

Nitrogen dioxide decomposes according to the reaction 2 no2(g) ⇌ 2 no(g) + o2(g) where kp = 4.48 × 10−13 at a certain temperature. if 0.70 atm of no2 is added to a container and allowed to come to equilibrium, what are the equilibrium partial pressures of no(g) and o2(g)