How are miles converted into kilometers? When did Joseph Priestley discover oxygen? What is an isomer? What are the longest rivers and the largest lakes?Now readers have fast, easy access to information that will satisfy the curiosities of even the most avid science buffs. Each Facts On File Science Dictionary defines all the terms that most people will ever need to know in language that's clear and concise.Numerous line drawings illustrate complex concepts, and extensive cross-references make searching for the right definition quick and easy.Written by prominent researchers, educators, and science writers, each dictionary is an ideal resource for students and general readers alike.Revised and expanded, this dictionary contains more than 3,000 entries covering basic terms as well as organs, biological processes, genera, and species.