Final answer:
Arsenic exists as atoms in a layered structure similar to graphite, with each atom forming covalent bonds to three other atoms within the sheet.
Step-by-step explanation:
Arsenic exists as atoms in its elemental form. It has a layered structure, similar to that of graphite. Each arsenic atom forms covalent bonds to three other atoms within the sheet. The crystal structure of arsenic is stable and contains puckered sheets of arsenic atoms.