✔ 最佳答案
boiling= from liquid to gas
meaning from a packed strucutre to a less packed structure.
consider the difference between different pressures.
at higher pressure the atoms are forced to pack more closely,
(in atmospheric pressure the atoms are packed less closely)
since they are packed more closely at high pressure, a higher energy is required for boiling, i.e. make the closely packed strucuture to become a less packed
structure.