Subatomic particles are considered as "building blocks" of matter because they are the fundamental constituents from which larger structures are composed. They are not merely properties of matter, but rather the entities that make up matter itself.
One of the key insights of modern physics is that matter is composed of a small number of elementary particles. These particles include electrons, quarks, and other fundamental particles. By combining these elementary particles in different ways, we can construct atoms, molecules, and eventually more complex structures.
The reason why subatomic particles are considered as building blocks is that they have distinct properties and behaviors of their own. They possess characteristics such as mass, charge, and spin, which are intrinsic to their nature. These particles interact with each other through fundamental forces, such as the electromagnetic and strong forces.
Additionally, experiments in particle physics have provided strong evidence for the existence of these elementary particles. High-energy particle accelerators have allowed scientists to probe matter at the smallest scales and discover new particles. The standard model of particle physics, which describes the known elementary particles and their interactions, has been successful in explaining a wide range of experimental results.
While subatomic particles are indeed associated with properties, they are more than just abstract properties of matter. They are the foundational constituents that make up the diverse array of matter we observe in the universe. The interactions and arrangements of these particles give rise to the rich variety of physical phenomena we observe at larger scales.