Final answer:
Metals are better conductors of heat and electricity than other solids due to their high electron density and metallic bonding, which allow electrons to move freely and efficiently transfer energy.
Step-by-step explanation:
Metals conduct heat and electricity far better than other solids due to their high electron density. This high density of free or delocalized electrons allows metals to conduct electric current efficiently. As these electrons do not belong to any single atom, they can move freely through the metal, which contributes to the metal's ability to conduct heat as well. This is because the electrons can easily absorb and transfer thermal energy, leading to a good conduction of heat. Moreover, the metallic bonding model explains this behaviour; as electrons enter one end of a piece of metal, an equal number flow outward from the other end, facilitating both electrical and thermal conduction.
Additionally, metals are known for their physical properties such as being shiny, malleable, ductile, and having high melting points and density. These properties are attributed to the strong bonds between the closely packed nuclei within the metal's structure, along with the movement of electrons that respond when light is shone on the metal's surface or when an electric field is applied.