Reference: Postulate Mechanics
The Matter
Most of us recognize matter as substance. The classical understanding of matter is as follows:
Matter has the characteristics of volume, density, weight, shape, color, etc. Matter can exist in the states of solid, liquid, and gas depending on factors like temperature and pressure. In solid state, matter holds its shape. In liquid state, matter takes the shape of its container. In gaseous state, matter fills the entire container. Matter has mass, which is very compact and rigid. It allows matter to be divided into very small particles. The motion of a material object, regardless of its size, can be treated mathematically as if it belongs to a point where all the mass of the object is concentrated. We call this point the center-of-mass.
The smallest particle of matter is an atom. The atom is actually configured of substances of different masses, such as, nucleons and electrons. This makes matter a composite substance.
.
