Oxygen allotropic forms

Oxygen, sulphur and selenium are known to exist in more than one allotropic form. 

This exists in two allotropic forms, oxygen, O2 and ozone, O3. 

Ozone. Ozone is an allotropic form of oxygen, O. Because it is an unstable gas, it must be generated at the point of use. Ozone is an effective, clean oxidizing agent possessing powerful antibacterial and antiviral properties. 

Basic physical properties of sulfur, selenium, and tellurium are indicated in Table 1.3. Downward the sulfur sub-group, the metallic character increases from sulfur to polonium, so that whereas there exist various non-metallic allotropic states of elementary sulfur, only one allotropic form of selenium is (semi)metallic, and the (semi)metallic form of tellurium is the most common for this element. Polonium is a typical metal. Physically, this trend is reflected in the electrical properties of the elements oxygen and sulfur are insulators, selenium and tellurium behave as semiconductors, and polonium is a typical metallic conductor. The temperature coefficient of resistivity for S, Se, and Te is negative, which is usually considered... 

Many elements including sulphur, carbon and oxygen can exist in two or more forms with different physical, and often chemical, properties such elements are said to exhibit allotropy and the different forms are known as allotropes or allotropic forms. 

An allotropic form of oxygen (03) (see Allotropy) of considerably greater degradative effect on rubber than oxygen itself. The ozone content of the atmosphere normally varies from 0.5 to 5.0 parts per 100 million (pphm) of air, but in certain areas (notably Los Angeles, USA) it may reach as much as 40 pphm of air. 

This exists in two allotropic forms, oxygen, 02 and ozone, O v Oxygen is a colourless gas which condenses to a pale blue liquid, b.p. 90 K, which is markedly paramagnetic indicating the presence of unpaired electrons (p. 229). Simple valence bond theory (as used in this book) would indicate the structure... 

Carbon is unique among chemical elements since it exists in different forms and microtextures transforming it into a very attractive material that is widely used in a broad range of electrochemical applications. Carbon exists in various allotropic forms due to its valency, with the most well-known being carbon black, diamond, fullerenes, graphene and carbon nanotubes. This review is divided into four sections. In the first two sections the structure, electronic and electrochemical properties of carbon are presented along with their applications. The last two sections deal with the use of carbon in polymer electrolyte fuel cells (PEFCs) as catalyst support and oxygen reduction reaction (ORR) electrocatalyst. 

Almost all the oxygen in the atmosphere ( 21%) is the allotropic form of molecular oxygen (Oj). This essential gas we breathe is the result of photosynthesis, which is how green plants (with chlorophyll) use the energy of the sun to convert carbon dioxide (CO ) and water to starches and sugars with molecular oxygen as the by-product. 

Owing to the allotropic forms of oxygen, to its various redox states, and related chemical species that are thermodynamically stable or exist for kinetic reasons, a lot of redox reactions are usually described. However, many of them are not really important for the common works, particularly for those in solutions consequently, only some of them have been described here. The publications cited earlier can be searched for data useful for the calculation of Gibbs energy or potentials of particular reactions. 

It is nevertheless obvious that such an clement may also exist as a polyatotnio molecule. Oxygen funiisbes us with an example of this for, in its ordinary condition it is a diatomic molecule, and in the allotropic form of oxone, a triatomic molecule ... 

Ozone (formula O3) An allotropic form of oxygen, produced by the action of electric discharges or of a certain ultraviolet wavelength of light on oxygen. It is a gas with a characteristic odor, and is a powerful oxidizing agent. 

The three known allotropic forms of oxygen are (1) the ordinary oxygen m the air, with two atoms per molecule, O , (2i ozone, O3, with three atoms per molecule, and (3) the rare, very unstable, nonmagnetic, pale-blue O4. The latter breaks down readily into two molecules of O . 

Oxygen has two allotropic forms 02, the oxygen that we breath and is necessary for life, and 03 ozone, which is harmful to breath but is beneficial when blocking damaging ultraviolet rays from the sun. Both forms are colorless. 

The red allotropic form of phosphorus is relatively nontoxic and, unlike white phosphorus, is not spontaneously flammable. Red phosphorus is, however, easily ignited. It is a polymeric form of phosphorus, thermally stable up to ca. 450°C. In its finally divided form, it has proved to be a powerful flame-retardant additive.18 Elemental red phosphorus is a highly efficient flame retardant, especially for oxygen-containing polymers such as polycarbonates and polyethylene terephthalate). Red phosphorus is particularly useful in glass-filled polyamide 6,6, where high processing temperature (about 280°C) excludes the use of most phosphorus compounds.19 In addition, coated red phosphorus is used to flame retard nylon electrical parts, mainly in Europe and Asia.20... 

Miss Katherine Williams, who worked for many years in the department on the chemistry of cooked fish, came first under Ramsay. It is said that he suggested that she should repeat the Cavendish experiment on air, but she chose something easier, the determination of the oxygen dissolved in water (p. 69). Later, when he and Miss K. Williams, at Bristol, were investigating an alleged allotropic form of nitrogen (Proc. Chem. Soc., 1886), he says that he suggested that she should... 

The generation of phosphine (and the phosphide anion) from elemental phosphorus for use in this type of reaction is common. While unreactive with neutral water (although undergoing rapid oxidation with oxygen at 34 °C), elemental phosphorus (white, P4) generates phosphine readily in basic medium. On heating above 400 °C, white phosphorus [P4] generates a different allotropic form known as red phosphorus in which a P-P bond within the fundamental P4 tetrahedron is broken and individual tetrahedra are linked in a polymeric chain. This form of elemental phosphorus is less reactive that white phosphorus, but still is quite useful for synthetic purposes. 

Metallurgically, uranium metal may exist in three allotropic forms orthorhombic, tetragonal, or body-centered cubic (EPA 1991), and may be alloyed with other metals to alter its structural and physical properties to suit the application. Like aluminum metal powder, uranium metal powder is autopyrophoric and can burn spontaneously at room temperature in the presence of air, oxygen, and water. In the same manner, the surface of bulk metal, when first exposed to the atmosphere, rapidly oxidizes and produces a thin surface layer of UO2 which resists oxygen penetration and protects the inner metal from oxidation. 

Oxygen exists in three allotropic forms, monatomic oxygen (O), diatomic oxygen (Oj), and triatomic oxygen (O3). The first of these is sometimes called nascent oxygen, and the last is more commonly known as ozone. Under most circumstances in nature, the diatomic form of oxygen predominates. In the upper part of the stratosphere, however, solar energy causes the breakdown of the diatomic form into the monatomic form, which may then recombine with diatomic molecules to form ozone. 

Oxygen exists in three allotropic forms. Allotropes are forms of an element with different physical and chemical properties. The three allotropes of oxygen are normal oxygen, or diatomic oxygen, or dioxygen nascent, atomic, or monatomic oxygen and ozone, or triatomic oxygen. The three allotropes differ from each other in a number of ways. 

---