What happens at the dew point? Clouds are formed

What causes rain?
dust particles can no longer support water droplets

The return of water vapor to the liquid form is called:
condensation

Water vapor is produced by the process of:
evaporation

What happens to air when it is heated by the sun?
It rises

Consider the growth of a 20-nm-diameter silicon nanowire onto a silicon wafer. the temperature of the wafer surface is maintained at 2400 k. assume the thermal conductivity of the silicon nanowire is 20 wm-1k-1 and all its surfaces including the tip are subjected to convection heat transfer with the coefficient h = 1×105 wm-2k-1 and t∞ = 8000 k. when the nanowire grows to l = 300 nm, what is the temperature of the nanowire tip (t (x =