what are the two allotropes of oxygen
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.