You put mass m1 of ice cooled to -20°C into mass m2 of water at 2°C. Both are in a thermally insulated chamber. In the final state of the system:

A. Everything turns to ice at a temperature below 0°C.

B. Everything melts and is at a temperature above 0°C.

C. There is a mixture of water and ice as the final state.

D. The water and ice never reach the same temperature.

E. There is not enough information to find the final temperature.

Uranium has two naturally occurring isotopes. 238u has a natural abundance of 99.3% and 235u has an abundance of 0.7%. it is the rarer 235u that is needed for nuclear reactors. the isotopes are separated by forming uranium hexafluoride uf6, which is a gas, then allowing it to diffuse through a series of porous membranes. 235uf6 has a slightly larger rms speed than 238uf6 and diffuses slightly faster. many repetitions of this procedure gradually separate the two isotopes. what is the ratio of the rms speed of 235uf6 to that of 238uf6? express your answer to five significant figures.