Which term refers to the physical substance made up of atoms and molecules?

The term that refers to the physical substance made up of atoms and molecules is matter. Matter encompasses everything that has mass and takes up space, including solids, liquids, and gases. It is characterized by its physical attributes, such as volume and mass, and consists of particles that are organized in various ways depending on the state of the matter.

Understanding matter is fundamental in the field of fire science because fire, as a chemical reaction, involves the interaction of matter (fuel, oxygen, and heat). Without matter, there would be nothing to ignite or burn, and thus the principles of combustion and fire prevention hinge on an understanding of the properties of matter.

Mass and weight, while related concepts, are not synonymous with matter. Mass refers specifically to the amount of matter in an object, while weight is the force exerted by gravity on that mass. Energy, on the other hand, is the capacity to do work or produce change and is a different conceptual framework altogether from the physical substance described by matter.