Metals are always better conductors of heat than most non-metals because they have __ to transfer heat other than molecules’ vibrations. *
A free electrons
B free atoms
C free protons
The correct answer and explanation is :
The correct answer is A) free electrons.
Metals are better conductors of heat than most non-metals due to the presence of free electrons in their atomic structure. Let’s break down why this is the case.
In metallic solids, the atoms are arranged in a regular, closely packed structure. These atoms have outer electrons that are not tightly bound to any particular atom, which allows them to move freely through the metal. These free electrons, often referred to as “delocalized electrons,” play a crucial role in the thermal conductivity of metals.
When heat is applied to one part of a metal, the free electrons gain energy. Since these electrons can move quickly throughout the metal, they are able to carry the energy from the hotter region to the cooler regions much more efficiently than molecules in non-metals. In essence, the free electrons act as the primary carriers of heat energy.
In contrast, non-metals, such as wood or rubber, typically lack free electrons. The atoms in non-metals are bound by stronger covalent or ionic bonds, which limit the movement of electrons. When heat is applied to a non-metal, the atoms or molecules vibrate more intensely, but the thermal energy is not transferred as efficiently as it is in metals. This process of heat transfer via vibrations (lattice vibrations or phonons) is much slower compared to the movement of free electrons in metals. Therefore, non-metals generally have lower thermal conductivity.
The reason why free protons (option C) are not responsible for heat transfer in metals is because protons are heavy particles that reside in the nucleus of atoms and are not free to move. Free atoms (option B) do not directly contribute to heat transfer either; it’s the free electrons that primarily facilitate this process.
In summary, metals are better conductors of heat than most non-metals because of the presence of free electrons that can move rapidly, transferring heat energy efficiently throughout the material.