Which description correctly defines the Particle Theory of Matter?

Which description correctly defines the Particle Theory of Matter?

• A. A model for chemical bonding only
• B. A theory that explains what matter is made of and how it behaves
• C. A method for separating mixtures
• D. A rule for balancing equations

Answer: (D)

Matter is made of tiny particles that are in constant motion and occupy space. The way these particles are arranged and how fast they move—which depends on energy and temperature—determines whether a substance is a solid, liquid, or gas, and explains changes in state, expansion, diffusion, and other behaviors of matter. This perspective shows what matter is made of and how it behaves in different conditions. It isn’t just about chemical bonds, nor a method for separating mixtures, nor a rule for balancing equations—those are separate ideas in chemistry.

Matter is made of tiny particles that are in constant motion and occupy space. The way these particles are arranged and how fast they move—which depends on energy and temperature—determines whether a substance is a solid, liquid, or gas, and explains changes in state, expansion, diffusion, and other behaviors of matter. This perspective shows what matter is made of and how it behaves in different conditions. It isn’t just about chemical bonds, nor a method for separating mixtures, nor a rule for balancing equations—those are separate ideas in chemistry.