Final answer:
Nonmetals are used as insulators in thermos bottles because they have high binding energy that makes it difficult for their electrons to move freely, which inhibits heat transfer and maintains the contents' temperature.
Step-by-step explanation:
Nonmetals are used as insulators in thermos bottles because they have properties that make them poor conductors of heat and electricity. In nonmetals, the atoms and molecules firmly hold on to their electrons, making it difficult for these charges to move freely. This is in stark contrast to metals, where outer electrons are more loosely bound, allowing for the free movement of electrons and making them good conductors. Thermos bottles utilize materials such as glass and plastics which are nonmetal insulators, as they prevent the transfer of heat via conduction, maintaining the desired temperature of the contents inside the bottle.
The higher binding energy (BE) of electrons in insulators implies that more energy is required to remove electrons from their atomic orbitals, which is why photons have a harder time ejecting electrons from insulators than from metals. This high BE is directly related to why nonmetals are poor conductors of heat and electricity. Thus, incorporating insulating materials into the design of a thermos bottle, including rubber supports and layers of air, contributes to its effectiveness in inhibiting all methods of heat transfer, such as conduction, convection, and radiation, to keep the contents at a stable temperature.