What describes the arrangement of atoms in diamond?

The arrangement of atoms in diamond is best described as being in a giant covalent structure. In diamond, each carbon atom is covalently bonded to four other carbon atoms in a three-dimensional tetrahedral arrangement. This extensive network of strong covalent bonds throughout the entire structure gives diamond its exceptional hardness and durability.

The concept of a giant covalent structure implies that there is no distinct or repeating unit, but rather a continuous array of atoms held together by covalent bonds, which is characteristic of materials like diamond and graphite. This strong bonding is responsible for many of diamond's notable properties, including its high melting point and its ability to refract light.

In contrast, an arrangement of atoms in layers, a simple molecular structure, or a metallic lattice does not accurately describe diamond's atomic configuration, making those choices less suitable representations of its structure. Layers suggest a more weakly bonded structure, while a simple molecular structure indicates discrete molecules, and a metallic lattice pertains to metals with delocalized electrons, all of which do not apply to the properties of diamond.