SAT Subject Test Chemistry

PART 2

REVIEW OF MAJOR TOPICS

CHAPTER 2

Atomic Structure and the Periodic Table of the Elements

NUCLEAR TRANSFORMATIONS AND STABILITY

At the same time advances in atomic theory were occurring, scientists were noticing phenomena associated with emissions from the nucleus of atoms in the form of “X-rays.” While Roentgen announced the discovery of X-rays, Becquerel was exploring the phosphorescence of some materials. Becquerel’s work received little attention until early in 1898, when Marie and Pierre Curie entered the picture. Searching for the source of the intense radiation in uranium ore, Marie and Pierre Curie used tons of it to isolate very small quantities of two new elements, radium and polonium, both radioactive. Along with Becquerel, the Curies shared the Nobel Prize in physics in 1903.