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.
Group 16 is the oxygen family. It consists of the elements oxygen, sulfur, selenium, tellurium, and polonium. Each has six of the desired eight electrons required for the octet in its highest energy level.
There are several known allotropes of oxygen. The most familiar is molecular oxygen (O 2), present at significant levels in Earth's atmosphere and also known as dioxygen or triplet oxygen.Another is the highly reactive ozone (O 3). Others include: 1  Atomic oxygen (O 1, a free radical).2  Singlet oxygen (O 2 *), either of two metastable states of molecular oxygen.ee also: Dioxygen in biological reactions. The common allotrope of elemental oxygen on Earth, O 2, is generally known as oxygen, but may be called dioxygen or molecular oxygen to distinguish it from the element itself.