Here's why:

* Monoatomic: This refers to elements existing as single atoms, like noble gases (He, Ne, Ar, etc.). Copper doesn't exist this way.

* Molecular: This refers to elements forming molecules by bonding with other atoms of the same element (like O2, N2). Copper doesn't form molecules with itself.

* Lattice: This describes a highly ordered, repeating arrangement of atoms, which is characteristic of metals. Copper atoms are arranged in a specific, repeating pattern called a face-centered cubic (FCC) lattice.

So, copper is a lattice element due to its structure in solid form.