What is the term for the direct transfer of heat between substances in contact?

The correct term for the direct transfer of heat between substances in contact is conduction. This process occurs when two objects at different temperatures are in physical contact, allowing heat to move from the warmer object to the cooler one. For example, when you touch a hot metal spoon, heat transfers from the spoon to your hand directly through conduction.

Convection, on the other hand, involves the movement of heat through fluids (liquids or gases) by the circulation of the fluid itself. This is commonly seen when heating a pot of water on a stove, where the water at the bottom becomes hot and rises while cooler water moves down to take its place.

Radiation is the transfer of heat in the form of electromagnetic waves, such as the warmth felt from the sun, which does not require a medium to transfer heat and can occur in a vacuum.

Insulation refers to materials used to reduce heat transfer between objects or environments, enhancing energy efficiency by preventing heat loss or gain. While insulation aids in reducing conduction, convection, or radiation, it does not involve the process itself.

Understanding these concepts is crucial, as they are foundational in the study of thermodynamics and energy transfer in Earth science and related fields.