Which of the following best describes why metals are malleable?

The malleability of metals is primarily due to the unique structure of metallic bonding, which allows the layers of atoms to slide past one another without breaking the metallic bond. In metallic materials, the atoms are arranged in a closely packed lattice structure surrounded by a "sea of electrons." This electron cloud is not fixed in one position; rather, it can move freely around the positively charged metal ions.

When a force is applied to a metal, the layers of metal atoms can shift relative to one another. The delocalized electrons continue to work effectively in maintaining the bond even as the atoms move, preventing the material from cracking and allowing it to deform instead. This quality enables metals to be hammered or rolled into thin sheets, which is the essence of malleability.

Other options do not accurately reflect the behavior of metals in this context. Rigid and immobile structures would imply that metals cannot deform, which contradicts their malleability. The formation of ionic lattices refers to ionic compounds rather than metals, and high covalent character is not a defining trait of metallic bonding, which is characterized by electron delocalization and not by strong directional bonds.