Many people have contributed to today's understanding of radioactivity. This page is intended to tell you a little about some of the most famous scientists in this field.
More details can befound in many CD-ROM encyclopedias.
They thought that matter could be made up of tiny building blocks. Isaac Newton , in 1687, said that the relationships we see between pressure, volume and temperature in gases could be explained if we assume that the gas is made of tiny particles. During the 19th Century, the modern idea of elements grew. In 1808, John Dalton suggested that each element was made of identical atoms. In 1811 Amedeo Avogadro proposed that these atoms could stick together to form molecules.