Select the best answer for the question.
13. What's mass?
A. A measure of the amount of matter an object contains
B. The force that gravity exerts upon an object
C. A measure of an element's attraction for electrons
D. The sum of the number of protons and neutrons in an atom
Answer (1)
The best answer for "What's mass?" is A: a measure of the amount of matter an object contains. Mass quantifies matter and is constant regardless of gravity, unlike weight. It is crucial for understanding inertia and other physical concepts. ;
