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 first trend is that elements in the periodic table are arranged into columns known as families representing similar chemical behavior. For example, members of the same family prefer to bond to the same number of hydrogen atomsâthe carbon family to four, nitrogen family to three, the oxygen family to two, etc.