The particle/wave duality in quantum mechanics refers to the observation that particles, such as electrons or photons, can exhibit both particle-like and wave-like properties. It is not directly related to the concept of mass/energy duality.
In the context of Einstein's theory of relativity, there is a relationship between mass and energy expressed by the famous equation E=mc², where E represents energy, m represents mass, and c represents the speed of light in a vacuum. This equation shows that mass and energy are interchangeable and can be converted into one another. However, this mass/energy equivalence is distinct from the particle/wave duality.
The particle/wave duality is specific to the behavior of particles at the quantum level and is described by the principles of quantum mechanics. It means that particles, such as electrons or photons, can exhibit characteristics of both discrete particles (with well-defined positions and momenta) and waves (with characteristics like interference and diffraction).
On the other hand, the mass/energy duality arises from the fundamental principles of relativity, where mass and energy are seen as different manifestations of the same underlying physical quantity. It is a consequence of the relationship between mass, energy, and the constant speed of light.
While there are connections between the concepts of particle/wave duality and mass/energy equivalence in terms of the fundamental principles of physics, they are distinct and refer to different aspects of our understanding of the physical world.