Atomic theory, electrochemistry (batteries and such) and analytical chemistry were developed by both sciences. If you think of it, physics and chemistry are inseparable from each other
Not necessarily but Mathematics is the language of Sciences such as Chemistry and Physics, and so if you are great at mathematics, it will certianly help with physics and chemistry.
Mathematics is a language that relates concepts to each other. Physics and chemistry can use mathematics as a tool for exploring and discovering relationships. On another view, physics and chemistry...