In 1811, Amedeo Avogadro (1776–1856) (born Lorenzo Romano Amedeo Carlo Avogadro di Quaregna e di Cerreto) looked at Gay-Lussac’s results and concluded that when they are at the same temperature and pressure, equal volumes of gas (like two balloons of the same size) contain the same number of “particles.” These particles can be individual atoms, molecules, or even a mixture thereof.
A major stumbling block to Dalton’s success was his poor experimental technique.
With a firm belief in atoms, impressive physical insight and armed with a few simple rules, Dalton was able to construct a table of relative weights, which he first presented in 1803 at a talk to the Literary and Philosophical Society of Manchester. In 1805, this effort first appeared in print, with a systematic explanation of the method appearing in 1808 when Dalton published the first volume of his book A New System of Chemical Philosophy. Here, with hydrogen as his reference, he gave the following relative weights: hydrogen (H) 1; nitrogen (N) 5; carbon (C) 5.4; oxygen (O) 7; phosphorus (P) 9; sulfur (S) 13 and so on, including several elements and compounds.
Modern atomic theory began in 1808 when Dalton published A New System of Chemical Philosophy.
Subscribe to the Newsletter
© 2024 Scott D. Bembenek
