Which is a form of heat transfer that is reduced by using a pot holder when taking a hot dish out of an oven?

Conduction

Explanation:

There are three forms of heat transfer:

- Conduction: this occurs when there is direct contact between the surfaces of two objects (or between different parts of the same substance at different temperatures) - the heat is transferred by the collisions between the molecules in the substance: the faster molecules (higher temperature) give part of their energy to the slower molecules (lower temperature), until the two surfaces are at the same temperature

- Convection: this occurs when heat is carried by a movement of molecules - so the molecules of a region at higher temperature move to a region of lower temperature, giving off their energy, until the two regions have same temperature. This only occurs in liquids and gases, and the main example is a pot of boiling water

- Radiation: this occurs when heat is carried by electromagnetic radiation. This method is the only one that can occur also in a vacuum, since it does not need a medium

In the example in the problem, when the hot dish is touched, heat is transferred by conduction (direct contact) : in order to reduce the heat transfer, a pot holder can be placed between our hand and the hot dish, so that the hot dish transfers heat to the holder instead of our hand.