(a) It is composed of two or more elements (b) It is a pure substance. (c) It cannot be separated into constituents by physical means (d) It is mixed in any proportion by mass
d no doesn't describe a compound
as because a compound is mixed in a constant proportion or ratio by mass.like hydrogen and oxygen are combined in 2:1 ratio to form a water molecules.hope this answer helps you. thank you for asking the question please mark it as the brainliest