The triple point of iodine is at 90 torr and 115°c. this means that liquid i₂: a) is more dense than i₂
b) cannot exist above 115°c
c) cannot exist at 1 atm pressure
d) cannot have a vapor pressure less than 90 torr.
e) can exist at pressure of 10 torr.

it is b that is the answer.

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.