Acetate is neither a metal nor a non-metal. It is a polyatomic ion, meaning it is a group of atoms that act together as a single unit with a charge.

Here's why:

* Acetate (CH3COO-) consists of carbon, hydrogen, and oxygen atoms, all of which are non-metals.

* Metals are generally characterized by their shiny appearance, good conductivity of heat and electricity, and malleability.

* Non-metals are typically dull, poor conductors, and brittle.

Acetate's properties are more similar to those of ionic compounds formed by metals and non-metals. However, it itself is not a metal or a non-metal.