Patients who waited more than 6 months to receive cataract surgery experienced more vision loss, a reduced quality of life and had an increased rate of falls compared with patients who had wait times of less than 6 weeks.
The chalcogens, the oxygen group, is located in column 16 of the periodic table. It contains the elements oxygen, sulfur, selenium, tellurium, polonium, and ununhexium (O, S, Se, Te, Po, and Uuh, respectively). These elements all contain six valence electrons and form 2- ions.
The elements nitrogen, phosphorus, arsenic, antimony and bismuth are referred to as the nitrogen family of element and occupy group V-A in the periodic table. The nitrogen family periodic table is shown below. Nitrogen and phosphorus are non metals, arsenic is a semi metal or non metal, antimony and bismuth are metals.