What is the call number?
A call number is series of letters and numbers that the library places on the spine of a book to tell you where an item is located in the library. The call number is kind of like GPS coordinates that lead you directly to the item.
A call number will also tell you which floor of the library an item is located on:
A call number will also tell you what subjects a book is dealing with:
The history and use of our earth's chemical elements : a reference guide
Q- Science (Broad Topic)
QD466 - Science - Chemistry (Narrow Topic within the Broad Topic)
.K74 tells you about the author Robert E. Krebs
1998 tells you the year of publication.