Final answer:
Current experimental evidence and theoretical models suggest that elementary particles are fundamental, yet scientific understanding is subject to change with advancements in technology and discovery.
Step-by-step explanation:
The question of whether all elementary particles are actually elementary is a profound one in the field of Physics. While we rely on experimental evidence and theoretical models to understand the fundamental nature of particles, it is important to note that scientific understanding evolves with technology and discovery. For instance, advanced technology has allowed us to observe individual atoms and to investigate the wave-particle duality of electrons through experiments similar to the Young double-slit experiment. While particle accelerators have been used in attempts to observe particles such as quarks directly, this has not yet been possible due to the limitations in energy and other factors. Therefore, we cannot say with absolute certainty that all particles deemed 'elementary' today will remain so in the future. As our tools and theories develop, so too might our understanding of the fundamental constituents of matter.