Answer:
AU is homoatomic
Explanation:
Homo-atomic Molecule: Molecules provided by unique one variety of particles are associated as Homo-atomic molecules
Ex: H2, N2, P4 etc.
Hetero-atomic Molecule: Particles constituted by several kinds of atoms are identified as Hetero-atomic molecules
Ex: CO2, NO2, CH4, HCl etc
As AU is homoatomic because this element is formed by only one atom
To learn more about atomic structure refer: