This module introduces the experimental discoveries that led to the development of quantum physics and transformed our understanding of the physical world. Students explore why classical Newtonian mechanics fails at atomic scales and how key experiments involving light, electrons, and atoms motivated a new theory of nature. Through simple mathematical models and problem solving, the module develops core quantum concepts such as quantisation, wave–particle duality, and atomic structure. Students also examine how these ideas underpin modern technologies, including lasers and spectroscopy. The module provides essential foundations for further study in physics and related disciplines, and connects fundamental theory with real experimental evidence encountered in laboratory courses.