Final answer:
The most workable model of matter is that it consists of particles in constant motion, reflecting our current understanding of atoms and molecules. Matter is categorized into pure substances and mixtures, with distinct behaviors observed in solids, liquids, and gases.
Step-by-step explanation:
The most workable model of matter is that physical matter exists in the form of particles in constant motion. This model reflects our current understanding that matter is made up of atoms, which bond together to form molecules. Atoms and molecules are constantly in motion, which is particularly evident in the behavior of gases and liquids. The other options have been ruled out because, while ancient philosophers like Democritus did conceptualize matter as indivisible atoms, we now know atoms can be divided into subatomic particles. Furthermore, the continuous model of matter has been replaced by the particle model, since matter is not a continuous substance but comprised of discrete particles.
Matter can be classified into two broad categories: pure substances and mixtures. Pure substances have a constant composition and consistent properties throughout, whereas mixtures can vary in composition and properties. The three common phases of matter—solid, liquid, and gas—demonstrate the different ways that atoms and molecules can organize themselves and how they move with respect to one another. Solids have a fixed volume and shape due to their atoms being closely packed in a regular array, exhibiting only vibrational motion. Liquids have a fixed volume but take the shape of their container because their particles are in close contact but can move past one another. Gases, on the other hand, neither have a fixed shape nor a fixed volume because their particles are much further apart and move freely.
In summary, when we consider all of this information and the current scientific consensus, the most accurate statement is that matter consists of particles in constant motion, as this reflects our understanding of atomic and molecular behavior in different states of matter.