On which floor of the library can I find books on Science (math, physics, biology and chemistry)?
Books in academic libraries are shelved according to their Library of Congress classification number, not by subject. This means that there is no single area for a subject as broad as Science. When you search for a book using the library website, the search results will tell you what floor your book is located on.
You may also wish to consult the subject research guides for more information on research in your discipline.