This best-selling dictionary contains over 9,000 entries on all aspects of science and provides comprehensive coverage of biology (including human biology), chemistry, physics, the earth sciences, and astronomy. Appendices cover the periodic table, geological time scale, and animal and plant classification. New features include virtual thumb tags for easy reference, expanded areas including astronomy and earth science and more features on key topics such as the Solar System and Genetically Modified Organisms. Also featured are short biographies of leading scientists and chronologies of specific subjects, including plastics, electronics and cell biology. Both concise and wide-ranging, this dictionary is an ideal handy reference work and great introduction for students and non-scientists alike.