Question

the amount of matter packed into a certain space is defined as ____________.

Explanation:

The definition given in the question matches the concept of density in physics. Density is calculated as mass per unit volume ($
ho=\frac{m}{V}$, where $
ho$ is density, $m$ is mass, and $V$ is volume), which represents how much matter (mass) is packed into a given space (volume).

Answer:

density