Earth science ?s I dont get these?

[Chaotic M]

there are a few ?s I dont understand truthfully. I have tried to figure them out and cant find it anywhere! please help , I have a test tomorrow
even if youre not willing to do them all, its fine. just an explanation atleast.
1) in what direction does water move when it is heated? like show with arrows, or explain so I can understand..thanks.

2)how can we best account for the air pressure drop between 6am and noon? a) condensation reduced to absolute humidity
b)the air was cooled by northerly winds d) the air was heated by sunlight. I think its A but Im not sure...

3)the sun's energy is often converted into potential energy by
a)melting ice b)heating of liquid water c) condensation of water vapor d) evaporation of water

4)which process requires the most absorption of energy by water? a) melting 1 gram of ice b) condensing 1 gram of water vapor c)vaporizing 1 gram of liquid water
ops #3 is wrong its...the choices are supposed to be:
melting ice 1
2 formation of fog in valley
3 freezing of water droplets on highway
4 precipitation of rain from thunderstorm