This episode introduces isotopes, first understood by Frederick Soddy, while studying decays of radioactive elements. Then we look at half-lives of elements, first calculated by Ernest Rutherford. This led to the first reasonable age of the Earth, calculated by Bertram Boltwood. Soddy and Kasimir Fajans independently figure out what happens to isotopes vis-a-vis the periodic table. Stefanie Horovitz first proves the existence of isotopes after tedious lab work to isolate two forms of lead. Soon after, J.J. Thompson builds a crude mass spectrometer and distinguishes two forms of neon. We discuss isotopes of uranium and hydrogen.<a rel="payment" href="https://www.patreon.com/thehistoryofchemistry">Support the Show.</a><ul> <li>Support my podcast at <a href='https://www.patreon.com/thehistoryofchemistry'>https://www.patreon.com/thehistoryofchemistry</a> </li> <li>Tell me how your life relates to chemistry! E-mail me at steve@historyofchem.com</li> <li>Get my book, O Mg! How Chemistry Came to Be, from World Scientific Publishing, <a href='https://www.worldscientific.com/worldscibooks/10.1142/12670#t=aboutBook'>https://www.worldscientific.com/worldscibooks/10.1142/12670#t=aboutBook</a> </li> </ul>

39: This Means War

Chemistry is everywhere, and involves everything. But how did chemistry get to be what it is? I'm Steve Cohen, a chemist and writer, bringing you The History of Chemistry. This podcast explores the development of chemistry from prehistoric times to the present, including the people and societies who made chemistry what it is today. The History of Chemistry is for you, whether you hated chemistry in high school, or got a PhD in inorganic chemistry. We'll explore how chemistry affected art, music, language, politics and vice-versa. Whether it's ancient Greek philosophers, medieval alchemists, or modern laboratory apparatus, it's all here. Don't forget to support my series at https://www.patreon.com/thehistoryofchemistry !