Senior Congregate Care. What is congregate housing? Congregate housing is an environment thatâs designed to cater for the housing needs of seniors and disabled persons. Residents of a congregate housing complex have private apartments but share a common dining room, kitchen facilities, and other amenities. The purpose of this arrangement is to allow seniors to continue living an independent life although assisted with such tasks like cooking.
The Russian chemist Dmitri Mendeleev was the first scientist to make a periodic table similar to the one used today. Mendeleev arranged the elements by atomic mass, corresponding to relative molar mass.
The development of the Periodic Table (pre-16) Most people regard Mendeleev as the initial formulator of the Periodic Table with the work of his contemporaries often ignored. One such chemist was the German Julius Lothar Meyer, (1830 - 1895), who was just four years older than the Russian. In 1864, five years before the first announcement of a Periodic System by Mendeleev, Meyer had produced a table of just 28 elements which he listed by their valence.