Physics is the study of how things work in nature. During the early phases of humanity's quest to comprehend nature, mathematics was "found." Nature works in some way, whether or not mathematics is used to describe it; we invented mathematics to describe how it works. By definition, chemistry is a discipline of applied physics that is more specific than materials science. It has a long history that dates back to the Middle Ages, which is why it is regarded as a field separate from physics.
In the early twentieth century, physics and chemistry came to a consensus that quantum mechanics and statistical thermodynamics are the foundation of all "world understanding" required to improve our daily lives.
Materials science focuses on materials at all levels, including metals, semiconductors, and ceramics, in addition to the materials that chemists work with. Materials science is concerned with the structure of materials, whereas chemistry is concerned with chemical reactions.