Question

the definition of a chemical is
a toxic substance made in a laboratory.
an unnatural material added to foods.
anything that has mass and takes up space.
any substance that has a definite composition

Explanation:

In chemistry, a chemical is defined as any substance with a definite composition. It doesn't have to be toxic, made in a lab, or unnatural. The description "anything that has mass and takes up space" is the definition of matter.

Answer:

any substance that has a definite composition