Final answer:
Helium atoms in pure helium do not form covalent, metallic, or ionic bonds; instead, they interact via weak London dispersion forces, which are a type of van der Waals force.
Step-by-step explanation:
The interactions between helium (He) atoms in pure helium are neither covalent, metallic, nor ionic bonds. Instead, helium atoms engage in a type of intermolecular force known as London dispersion forces, which are a subset of van der Waals forces. These are weak intermolecular forces that arise due to the temporary fluctuations in the electron distribution within the atoms, leading to a temporary dipole moment that can induce a similar dipole in a neighboring atom. Helium atoms are monoatomic and nonpolar, and since they have a closed shell electron configuration with a full valence shell, they do not tend to form chemical bonds through electron sharing or transfer. Thus, the correct answer is D. None of the above, as helium atoms exhibit dispersion forces, which are much weaker than the other types of bonds mentioned.