Here's why:
* Atoms are the fundamental building blocks of matter. They are the smallest unit of an element that retains the chemical properties of that element.
* Atoms are composed of subatomic particles: protons, neutrons, and electrons.
* Subatomic particles are not considered "complete matter" on their own. They lack the defining characteristics of an element, such as chemical properties.
While atoms are the smallest unit of "complete matter," they can be broken down further into their constituent subatomic particles. However, these subatomic particles are not considered "complete matter" because they lack the properties that define a specific element.
