* Electronic Structure: Arsenic is a metalloid, meaning it has properties of both metals and nonmetals. Its electronic structure is such that it doesn't readily allow for free movement of electrons, which is essential for good conductivity.
* Crystal Structure: Arsenic has a layered crystal structure, which makes it difficult for heat and electricity to flow easily through the material.
In contrast:
* Good Conductors: Metals like copper, silver, and gold are excellent conductors of heat and electricity because they have a sea of free electrons that can easily carry charge and energy.
* Poor Conductors: Nonmetals like sulfur and phosphorus are poor conductors because their electrons are tightly bound to their atoms, making it difficult for them to move freely.
Therefore, arsenic, while a metalloid, falls closer to the nonmetal side in terms of its conductivity.
