Aliquid is placed in an evacuated, sealed flask. when will this closed system reach dynamic equilibrium? when all of the liquid has evaporated to form a vapor when liquid and vapor are present but evaporation stops when the rate of evaporation equals the rate of condensation when the volume of liquid equals the volume of vapor

If we ignore temperature equilibrium (since no data given), then dynamic equilibrium when the rate of evaporation equals the rate of condensation over a finite period of time and under constant temperature.

This is because at *dynamic* equilibrium, evaporation and condensation are both taking place continuously.  If the rates are equal, then the mass of vapour and mass of liquid phases do not change, hence equilibrium.  Dynamic because changes are still taking place.

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant. 

The answer is celsius