A History of Science by Mary Cruse;

Author:Mary Cruse; [Cruse, Mary]
Language: eng
Format: epub
Tags: History
ISBN: 9781398810020
Publisher: Vearsa

Did You Know?

Before Jöns Jacob Berzelius established the practice of referring to all chemical elements by letters, some were represented with symbols, such as a circle with a line through it or a plus sign inside.

John Dalton published his atomic theory in 1808.

Shortly after this, a Swedish chemist named Jöns Jacob Berzelius used Dalton’s atomic theory to create a table of elements, with the order based on their atomic weights relative to one another. Building on this system, Berzelius invented a system of naming the various elements; each was marked by one or two letters – for instance, H for hydrogen, Mg for magnesium. In 1869, Dmitri Mendeleev, a Russian chemist, took Berzelius’ table and completely flipped it, so that the elements were arranged horizontally in order of their atomic weight and placed into vertical columns containing elements with similar properties. Mendeleev’s table demonstrated a clear order to the elements, and the arrangement could even be used to identify gaps in the table, where presently undiscovered elements should sit. After these missing elements – gallium, scandium and germanium – were discovered in the 1870s and 1880s, it became clear than Mendeleev’s table had cracked the code and captured the inherent order within the chemical elements.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.