Question

A substance that has a uniform composition and is able to be separated by physical means is a(n)

Solution

Heterogeneous Mixture

Element

Compound

Answer 1

A solution - you can evaporate the solvent and obtain the soluted substance.

A heterogenous mixture is obviously not uniform, so it's not a possible answer.
An element is the simplest building block of substances that carries chemical properties. You can only convert elements through nuclear reactions.
A compound is made of atoms bound together through chemical bonds. Physical methods can't break it apart.