What term is used to describe the measure of the quantity of matter in an object?

The term that describes the measure of the quantity of matter in an object is mass. Mass is an intrinsic property of matter and is often measured in kilograms or grams. It reflects how much matter is present in an object, regardless of the object's location or the gravitational force acting upon it.

Weight, on the other hand, refers to the force exerted by gravity on an object’s mass and varies depending on the gravitational field strength at a given location. Volume measures the amount of three-dimensional space an object occupies, while density is the mass per unit volume of a substance. These distinctions highlight why mass specifically refers to the quantity of matter, making it the correct answer to the question.