1.how vapour pressure is related to temperature ?

​2. Xenon crystallises in FCC lattice and the edge length of unit cell is 620pm . what is the next nearest neigbourhood distance?

@ shradha 
in the case of vapour pressure what u need to understand is that , its a pressure which created in the surface of liquid , 
so, it will increase as soon as u increase the temperature , and it will decrease if u will decrease the temp . 
once you increase the temp , more and more molecules of liquid will evaporate and that will create more pressure on the surface of liquid , so, vapour pressure will be more . 
COMING TO THE 2ND QUES 
a = 620 pm 
as per the fcc lattice formula 
2x = a root 2 
x = a/root2 = 620/ root 2   pm 
x = 438.406 pm 
x here is the nearest neighbour distance . 

HOPE IT CLEARS YOUR DOUBT 

ALL THE BEST ..