Answer: The material that is not a mixture; it has the same properties all the way through is called a substance.
Explanation:
A pure substance is a form of matter that has a constant composition and properties that are constant throughout the sample. Hence, it cannot be separated by physical means. Example: Gold
Mixture is a substance which has two or more components which do not combine chemically and do not have any fixed ratio in which they are present. They can be separated by physical means as well. Example: Air
Thus the material that is not a mixture; it has the same properties all the way through is called a substance.