In physics the amount of matter contained in an object is called what physical quantity?

Introduction / Context:
Physics distinguishes between several basic properties of objects, such as mass, weight, volume and density. A very common conceptual question in exams asks what we mean by the amount of matter in an object, which helps test whether the student can separate mass from weight.

Given Data / Assumptions:

- We are dealing with the fundamental definition of the quantity that measures the amount of matter. - Four options are given, each naming a physical quantity or related word. - Standard school physics definitions apply.

Concept / Approach:
Mass is defined as the amount of matter contained in a body. It is an intrinsic property and does not change with location. Weight, on the other hand, is the force with which Earth or another body attracts the object, and it depends on gravitational acceleration. Volume measures the space occupied by the object, and the word space by itself is not a defined physical quantity here. Therefore, the correct answer is mass.

Step-by-Step Solution:
Step 1: Recall the school level definition that mass is the amount of matter present in a body. Step 2: Remember that weight is calculated as mass multiplied by gravitational acceleration and is a force, not the matter itself. Step 3: Note that volume describes how much three dimensional space an object takes up and is measured in cubic units. Step 4: Understand that the option space is not a specific physical quantity used to describe matter here. Step 5: Therefore identify mass as the physical quantity representing the amount of matter.

Verification / Alternative check:
Any basic physics textbook will clearly define mass as the amount of matter contained in a body, while weight is treated in the chapter on gravitation as a force that can vary with gravitational acceleration. Checking examples like an astronaut on the Moon, whose mass remains the same while weight changes, further confirms that mass is associated with matter and weight with gravitational force.

Why Other Options Are Wrong:
Weight is a force that depends on gravity and is not a direct measure of the amount of matter. Volume measures the space occupied by the object, not the quantity of matter inside it. Space, as given, is a descriptive word and not used as the standard name for a basic physical quantity in this context.

Common Pitfalls:
Many students confuse mass and weight in everyday language, because we commonly say we weigh a certain number of kilograms, even though kilogram is a unit of mass. In physics, keeping the definitions precise helps avoid this confusion. Exam questions often exploit this everyday language mix up, so it is important to remember that the amount of matter is always mass.

Final Answer:
The physical quantity that measures the amount of matter in an object is called Mass.