Oxygen


This includes information on atomic properties isotopes, and molecular and bulk forms. Chemical properties and its astronomical, geological, and biological abundance will also be included. Particular individuals and groups who are expert may also be mentioned. Information about the cultural ,institutional sociological, and historical aspects of oxygen will also included here.	Science Chemistry Substances Elements

In Biology, Oxygen is essential to animal life, though it is less important for plant life and is poisonous to certain microbes.

In earth science, it is the single most abundant element on earth. It is the second major component in the atmosphere, is a component of the hydrosphere, and is important in the great majority of rocks and minerals.

Astronomy. Oxygen is the third most abundant element in most of the universe, certainly in the Solar system, but it is seldom found free and is usually found in combination with other elements.

Chemical properties

Compounds

Oxygen reacts with hydrogen to form water, H₂0, and hydrogen peroxide, H₂0₂.

Oxygen combines with magnesium to form magnesium oxide MgO. This is a chemically reactive compound that combines with others.

Oxygen combines with Aluminum to form aluminum oxide, Al₂O₃, or alumina

Oxygen reacts with carbon to form two principal oxides: Carbon monoxide, CO, and carbon dioxide, CO₂. There is a series of oxygen containing organic chemicals, including formaldehyde, H₂CO.

Oxygen combines with nitrogen to form a variety of oxides. The simplest is nitric oxide NO.

Oxygen combines with sulfur to form two principal oxides, SO₂ as the more common, and SO₃.

Oxygen reacts with silicon to form silicon dioxide, SiO₂, also known as silica. This is one of the more stble compounds in nature and is found in numerous non0crystalline and crystalline forms.

Oxygen reacts with iron to form two principal oxides, FeO and Fe₂O₃. Both of these are solids.

Physical properties

There are two allotropes, or forms of Oxygen; Ozone, and molecular oxygen

Molecular forms

O Monatomic
- Ionized forms
  - O⁺
  - O^-
- Bulk properties
O₂ Diatomic
- Ionized forms
  - O₂⁺
  - O₂^-
- Molecular weight 31.9988
- Bulk properties
O₃ Ozone
- Ionized forms
  - O₃⁺
  - O₃^-
- Bulk properties

Atomic properties

Number: 8
Weight (mean) 15.9994

Isotopes

Nuclear composition	Mass	Abundance
16O8	15.994914622(2)	99.762%
17O8	16.9991315(2)	0.038%
18O8	17.9991604(2)	0.200%

Thermodynamic properties

Oxygen has a melting/freezing point of 54.36 K (-218.79 °C, -361.82 °F)

Oxygen has a boiling point of 90.20 K (-182.95 °C, -297.31 °F)