By the middle of the 19th century, a large number of chemical elements had been discovered, their atomic masses determined, and a large number of physical properties measured. The chemists of the time began to group the elements according to properties, giving rise to the first periodic tables of the elements. Periodic classifications allow us to see the similarities and differences between the different elements and predict properties of elements that were yet to be discovered.
In 1869, Dimitri Mendeleev and Lothar Meyer independently proposed periodic classifications of the elements, which are based on their organization in increasing order of atomic masses. This ordering grouped together elements with similar physical properties.
We use cookies

We use cookies on our website. Some of them are essential for the operation of the site, while others help us to improve this site and the user experience (tracking cookies). You can decide for yourself whether you want to allow cookies or not. Please note that if you reject them, you may not be able to use all the functionalities of the site.