Final answer:
The statement that a system at a high temperature possesses more heat than one at a lower temperature is NOT true regarding heat transfer. Heat transfer depends on temperature differences, not just the temperature itself, and can also occur during phase changes without temperature changes.
Step-by-step explanation:
The question relates to the concept of heat transfer in the context of thermal physics. Regarding the provided options, the one that is NOT true is the statement that a system at a high temperature possesses more heat than a system at a lower temperature. This notion is incorrect because the amount of heat a system has is determined not only by temperature but also by its mass, specific heat capacity, and phase. Heat is the energy in transit due to a temperature difference between two systems or between a system and its surroundings. Thermal conductivity is a property that quantifies how well a material can conduct heat, and it does not depend on temperature. Ultimately, heat transfer requires a temperature difference and occurs spontaneously from a hotter to a cooler system, regardless of their intrinsic heat content.
The process in which heat must transfer energy to or from a system in order to cause a phase change occurs without a temperature change in the system. This is a key concept that differentiates heat involved in phase changes from heat involved in changing the temperature of a substance.
Option D, which suggests that pressure difference causes heat transfer, is also not true. While pressure can impact the boiling and melting points of substances and thus influence the conditions under which heat transfer occurs, it is not the driving force for heat transfer itself; temperature difference is. Additionally, options related to one-way heat flow and the negative heat transfer of energy are incorrect, as heat transfer is not restricted in these ways.