The dictionary contains over 1500 basic scientific words divided into three main groups physics, chemistry and biology Some words may appear in two of the groups, e g motor1 in physics, motor2 in biology. Related words from other areas of science are also included: the physics part contains words from meteorology, chemistry contains words from geology and health and hygiene are found in biology. In addition the entries are arranged within the three main groups according to meaning, to help the reader to obtain a broad understanding of a particular area of science.