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Dioxygen Difluoride
Dioxygen difluoride is a compound of fluorine and oxygen with the molecular formula O2F2. It can exist as an orange-red colored solid which melts into a red liquid at . It is an extremely strong oxidant and decomposes into oxygen and fluorine even at at a rate of 4% per its lifetime at room temperature is thus extremely short. Dioxygen difluoride reacts vigorously with nearly every chemical it encounters (including ordinary ice) leading to its onomatopoeic nickname FOOF (a play on its chemical structure and its explosive tendencies). Preparation Dioxygen difluoride can be obtained by subjecting a 1:1 mixture of gaseous fluorine and oxygen at low pressure (7–17 mmHg (0.9–2.3 kPa) is optimal) to an electric discharge of 25–30 mA at 2.1–2.4 kV. A similar method was used for the first synthesis by Otto Ruff in 1933. Another synthesis involves mixing and in a stainless steel vessel cooled to , followed by exposing the elements to bremsstrahlung ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical reaction, which may involve interactions with other substances. In this process, bonds between atoms may be broken or new bonds formed or both. There are four major types of compounds, distinguished by how the constituent atoms are bonded together. Molecular compounds are held together by covalent bonds; ionic compounds are held together by ionic bonds; intermetallic compounds are held together by metallic bonds; coordination complexes are held together by coordinate covalent bonds. Non-stoichiometric compounds form a disputed marginal case. A chemical formula specifies the number of atoms of each element in a compound molecule, usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ozone Difluoride
Oxygen fluorides are compounds of elements oxygen and fluorine with the general formula , where ''n'' = 1 to 6. Many different oxygen fluorides are known: * Oxygen monofluoride (OF) *Oxygen difluoride () *Dioxygen difluoride () * Trioxygen difluoride or ozone difluoride () * Tetraoxygen difluoride () * Pentaoxygen difluoride () * Hexaoxygen difluoride () * Dioxygen monofluoride or fluoroperoxyl () Oxygen fluorides are strong oxidizing agents with high energy and can release their energy either instantaneously or at a controlled rate. Thus, these compounds attracted much attention as potential oxidizers in jet propulsion systems. Synthesis, properties and reactions Oxygen difluoride () A common preparative method involves fluorination of sodium hydroxide: : is a colorless gas at room temperature and a yellow liquid below 128 K. Oxygen difluoride has an irritating odor and is poisonous. It reacts quantitatively with aqueous haloacids to give free halogens: : It can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Covalent Radius Of Fluorine
The covalent radius of fluorine is a measure of the size of a fluorine atom; it is approximated at about 60 picometres. Since fluorine is a relatively small atom with a large electronegativity, its covalent radius is difficult to evaluate. The covalent radius is defined as half the bond lengths between two neutral atoms of the same kind connected with a single bond. By this definition, the covalent radius of F is 71 pm. However, the F-F bond in F2 is abnormally weak and long. Besides, almost all bonds to fluorine are highly polar because of its large electronegativity, so the use of a covalent radius to predict the length of such a bond is inadequate and the bond lengths calculated from these radii are almost always longer than the experimental values. Bonds to fluorine have considerable ionic character, a result of its small atomic radius and large electronegativity. Therefore, the bond length of F is influenced by its ionic radius, the size of ions in an ionic crystal, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pi Bond
In chemistry, pi bonds (π bonds) are covalent chemical bonds, in each of which two lobes of an orbital on one atom overlap with two lobes of an orbital on another atom, and in which this overlap occurs laterally. Each of these atomic orbitals has an electron density of zero at a shared nodal plane that passes through the two bonded nuclei. This plane also is a nodal plane for the molecular orbital of the pi bond. Pi bonds can form in double and triple bonds but do not form in single bonds in most cases. The Greek letter π in their name refers to p orbitals, since the orbital symmetry of the pi bond is the same as that of the p orbital when seen down the bond axis. One common form of this sort of bonding involves p orbitals themselves, though d orbitals also engage in pi bonding. This latter mode forms part of the basis for metal-metal multiple bonding. Properties Pi bonds are usually weaker than sigma bonds. The C–C double bond, composed of one sigma and o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lone Pair
In chemistry, a lone pair refers to a pair of valence electrons that are not shared with another atom in a covalent bondIUPAC ''Gold Book'' definition''lone (electron) pair''/ref> and is sometimes called an unshared pair or non-bonding pair. Lone pairs are found in the outermost electron shell of atoms. They can be identified by using a Lewis structure. Electron pair, Electron pairs are therefore considered lone pairs if two electrons are paired but are not used in chemical bonding. Thus, the number of electrons in lone pairs plus the number of electrons in bonds equals the number of valence electrons around an atom. Lone pair is a concept used in valence shell electron pair repulsion theory (VSEPR theory) which explains the Molecular geometry, shapes of molecules. They are also referred to in the chemistry of Lewis acids and bases. However, not all non-bonding pairs of electrons are considered by chemists to be lone pairs. Examples are the transition metals where the non-bonding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triple Bond
A triple bond in chemistry is a chemical bond between two atoms involving six Electron pair bond, bonding electrons instead of the usual two in a covalent bond, covalent single bond. Triple bonds are stronger than the equivalent covalent bond, single bonds or double bond, double bonds, with a bond order of three. The most common triple bond is in a nitrogen N2 molecule; the second most common is that between two carbon atoms, which can be found in alkynes. Other functional groups containing a triple bond are cyanides and isocyanides. Some diatomic molecules, such as diphosphorus and carbon monoxide, are also triple bonded. In skeletal formula, skeletal formulae the triple bond is drawn as three parallel lines (≡) between the two connected atoms. Bonding Triple bonding can be explained in terms of orbital hybridization. In the case of acetylene, each carbon atom has two sp orbital, sp-orbitals and two p-orbitals. The two sp-orbitals are linear, with 180° bond angles, and occupy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioxygen
There are several known allotropes of oxygen. The most familiar is molecular oxygen (), present at significant levels in Earth's atmosphere and also known as dioxygen or triplet oxygen. Another is the highly reactive ozone (). Others are: * Atomic oxygen (), a free radical. * Singlet oxygen (), one of two metastable states of molecular oxygen. * Tetraoxygen (), another metastable form. * Solid oxygen, existing in six variously colored phases, of which one is octaoxygen (, red oxygen) and another one metallic (ζ-oxygen). Atomic oxygen Atomic oxygen, denoted O or O1, is very reactive, as the individual atoms of oxygen tend to quickly bond with nearby molecules. Its lowest-energy electronic state is a spin triplet, designated by the term symbol 3P. On Earth's surface, it exists naturally for a very short time. In outer space, the presence of ample ultraviolet radiation results in a low Earth orbit atmosphere in which 96% of the oxygen occurs in atomic form. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1 E-12 M
1 (one, unit, unity) is a number, numeral, and glyph. It is the first and smallest positive integer of the infinite sequence of natural numbers. This fundamental property has led to its unique uses in other fields, ranging from science to sports, where it commonly denotes the first, leading, or top thing in a group. 1 is the unit of counting or measurement, a determiner for singular nouns, and a gender-neutral pronoun. Historically, the representation of 1 evolved from ancient Sumerian and Babylonian symbols to the modern Arabic numeral. In mathematics, 1 is the multiplicative identity, meaning that any number multiplied by 1 equals the same number. 1 is by convention not considered a prime number. In digital technology, 1 represents the "on" state in binary code, the foundation of computing. Philosophically, 1 symbolizes the ultimate reality or source of existence in various traditions. In mathematics The number 1 is the first natural number after 0. Each natural numbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioxygen Difluoride 2D
There are several known allotropes of oxygen. The most familiar is molecular oxygen (), present at significant levels in Earth's atmosphere and also known as dioxygen or triplet oxygen. Another is the highly reactive ozone (). Others are: *Atomic oxygen (), a free radical. *Singlet oxygen (), one of two metastable states of molecular oxygen. *Tetraoxygen (), another metastable form. *Solid oxygen, existing in six variously colored phases, of which one is octaoxygen (, red oxygen) and another one metallic (ζ-oxygen). Atomic oxygen Atomic oxygen, denoted O or O1, is very reactive, as the individual atoms of oxygen tend to quickly bond with nearby molecules. Its lowest-energy electronic state is a spin triplet, designated by the term symbol 3P. On Earth's surface, it exists naturally for a very short time. In outer space, the presence of ample ultraviolet radiation results in a low Earth orbit atmosphere in which 96% of the oxygen occurs in atomic form. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VSEPR Theory
Valence shell electron pair repulsion (VSEPR) theory ( , ) is a conceptual model, model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. It is also named the Gillespie-Nyholm theory after its two main developers, Ronald Gillespie and Ronald Sydney Nyholm, Ronald Nyholm. The premise of VSEPR is that the valence electron pairs surrounding an atom tend to repel each other. The greater the repulsion, the higher in energy (less stable) the molecule is. Therefore, the VSEPR-predicted molecular geometry of a molecule is the one that has as little of this repulsion as possible. Gillespie has emphasized that the electron-electron repulsion due to the Pauli exclusion principle is more important in determining molecular geometry than the electrostatic repulsion. The insights of VSEPR theory are derived from topological analysis of the electron density of molecules. Such quantum chemical topology (QCT) metho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Symmetry
In chemistry, molecular symmetry describes the symmetry present in molecules and the classification of these molecules according to their symmetry. Molecular symmetry is a fundamental concept in chemistry, as it can be used to predict or explain many of a molecule's chemical property, chemical properties, such as whether or not it has a molecular dipole moment, dipole moment, as well as its allowed spectroscopy, spectroscopic transitions. To do this it is necessary to use group theory. This involves classifying the states of the molecule using the irreducible representations from the character table of the symmetry group of the molecule. Symmetry is useful in the study of molecular orbitals, with applications to the Hückel method, to ligand field theory, and to the Woodward–Hoffmann rules. Many university level textbooks on physical chemistry, quantum chemistry, spectroscopy and inorganic chemistry discuss symmetry. Another framework on a larger scale is the use of crystal sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
