Hydrogen (pronounced /ˈhaɪdrədʒən/[2]) is the chemical element A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. The term is also used to refer to a pure chemical substance composed of atoms with the same number of protons. Common examples of elements are iron, copper, silver, gold, hydrogen, carbon, with atomic number In chemistry and physics, the atomic number is the number of protons found in the nucleus of an atom and therefore identical to the charge number of the nucleus. It is conventionally represented by the symbol Z. The atomic number uniquely identifies a chemical element. In an atom of neutral charge, atomic number is equal to the number of electrons 1. It is represented by the symbol A chemical symbol is an abbreviation or shortened version of the name of a chemical element, generally assigned in relation to its Latin name. Natural elements all have symbols of one or two letters; some man-made elements have temporary symbols of three letters. Each element is usually denoted by the first letter of its English or Latin language H. At standard temperature and pressure In physical sciences, standard conditions for temperature and pressure are standard sets of conditions for experimental measurements, to allow comparisons to be made between different sets of data. The most used standards are those of the International Union of Pure and Applied Chemistry (IUPAC) and the National Institute of Standards and, hydrogen is a colorless In the field of optics, transparency is the physical property of allowing light to pass through a material. The opposite property is opacity. Transparent materials are clear . Translucent materials allow light to pass through them only diffusely (i.e. they cannot be seen through clearly), odorless, nonmetallic Nonmetal, or non-metal, is a term used in chemistry when classifying the chemical elements. On the basis of their general physical and chemical properties, every element in the periodic table can be termed either a metal or a nonmetal, tasteless Taste is a form of direct chemoreception and is one of the traditional five senses. It refers to the ability to detect the flavor of substances such as food, certain minerals, and poisons. In humans and many other vertebrate animals the sense of taste partners with the less direct sense of smell, in the brain's perception of flavor. In the West,, highly flammable Combustion or burning is a complex sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat or both heat and light in the form of either a glow or flames, appearance of light flickering diatomic Diatomic molecules are molecules composed only of two atoms, of either the same or different chemical elements. The prefix di- means two in Greek. Common diatomic molecules are hydrogen, nitrogen, oxygen, and carbon monoxide. Most elements aside from the noble gases form diatomic molecules when heated, but high temperatures—sometimes thousands gas In physics, a gas is a state of matter, consisting of a collection of particles without a definite shape or volume that are in more or less random motion with the molecular formula A chemical formula is a way of expressing information about the atoms that constitute a particular chemical compound, and how the relationship between those atoms changes in chemical reactions. For molecular compounds it is also known as the molecular formula, and identifies each constituent element by its chemical symbol and indicates the number H2. With an atomic weight Atomic weight is a dimensionless physical quantity, the ratio of the average mass of atoms of an element (from a given source) to 1/12 of the mass of an atom of carbon-12. The term is usually used, without further qualification, to refer to the standard atomic weights published at regular intervals by the International Union of Pure and Applied of 1.00794 u The unified atomic mass unit or atomic mass unit , or dalton (Da) or, sometimes, universal mass unit (u), is a unit of mass used to express atomic and molecular masses. It is the approximate mass of a hydrogen atom, a proton, or a neutron, hydrogen is the lightest element.
Hydrogen is the most abundant The abundance of a chemical element measures how relatively common the element is, or how much of the element there is by comparison to all other elements. Abundance may be variously measured by the mass-fraction , or mole-fraction (fraction of atoms, or sometimes fraction of molecules, in gases), or by volume fraction. Measurement by volume- chemical element, constituting roughly 75% of the universe's elemental mass.[3] Stars A star is a massive, luminous ball of plasma that is held together by gravity. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth. Other stars are visible in the night sky, when they are not outshone by the Sun. Historically, the most prominent stars on the celestial sphere were grouped together into in the main sequence are mainly composed of hydrogen in its plasma In physics and chemistry, plasma is a partially ionized gas, in which a certain proportion of electrons are free rather than being bound to an atom or molecule. The ability of the positive and negative charges to move somewhat independently makes the plasma electrically conductive so that it responds strongly to electromagnetic fields. Plasma state. Elemental hydrogen is relatively rare on Earth Earth is the third planet from the Sun, and the largest of the terrestrial planets in the Solar System in terms of diameter, mass and density. It is also referred to as the World, the Blue Planet,[note 3] and Terra.[note 4]. Industrial production is from hydrocarbons In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. With relation to chemical terminology, aromatic hydrocarbons or arenes, alkanes, alkenes and alkyne-based compounds composed entirely of carbon or hydrogen are referred to as "pure" hydrocarbons, whereas other hydrocarbons with bonded such as methane with most being used "captively" at the production site. The two largest uses are in fossil fuel Fossil fuels or mineral fuels are fuels formed by natural resources such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years. These fuels contain high percentage of carbon and hydrocarbons processing (e.g., hydrocracking In petroleum geology and chemistry, cracking is the process whereby complex organic molecules such as kerogens or heavy hydrocarbons are broken down into simpler molecules by the breaking of carbon-carbon bonds in the precursors. The rate of cracking and the end products are strongly dependent on the temperature and presence of any catalysts) and ammonia Ammonia is a compound of nitrogen and hydrogen with the formula NH3. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers. Ammonia, either directly or indirectly, is also a building block production mostly for the fertilizer market. Hydrogen may be produced from the electrolysis of water Electrolysis of water is the decomposition of water into oxygen (O2) and hydrogen gas (H2) due to an electric current being passed through the water. This electrolytic process is rarely used in industrial applications since hydrogen can be produced more affordably from fossil fuels or other hydrogen production Hydrogen is commonly produced by extraction from hydrocarbon fossil fuels via a chemical path. Hydrogen may also be extracted from water via biological production in an algae bioreactor, or using electricity , chemicals (by chemical reduction) or heat (by thermolysis); these methods are less developed for bulk generation in comparison to chemical methods like the reforming of natural gas.[4]
The most common isotope Isotopes are any of the different types of atoms (nuclides) of the same chemical element, each having a different atomic mass (mass number). Isotopes of an element have nuclei with the same number of protons (the same atomic number) but different numbers of neutrons. Therefore, isotopes of the same element have different mass numbers (number of of hydrogen is protium A hydrogen atom is an atom of the chemical element hydrogen, and an example of a Boson. The electrically neutral atom contains a single positively-charged proton and a single negatively-charged electron bound to the nucleus by the Coulomb force. The most abundant isotope, hydrogen-1, protium, or light hydrogen, contains no neutrons; other isotopes (name rarely used, symbol H) with a single proton The proton is a subatomic particle with an electric charge of +1 elementary charge. It is found in the nucleus of each atom but is also stable by itself and has a second identity as the hydrogen ion, 1H+. It is composed of 3 even more fundamental particles comprising two up quarks and one down quark and no neutrons The neutron is a subatomic particle with no net electric charge and a mass slightly larger than that of a proton. In ionic compounds In chemistry, an ionic compound is a chemical compound in which ions are held together in a lattice structure by ionic bonds. Usually, the positively charged portion consists of metal cations and the negatively charged portion is an anion or polyatomic ion. Ions in ionic compounds are held together by the electrostatic force between oppositely it can take a negative charge (an anion An ion is an atom or molecule where the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge known as a hydride Hydride is the name given to the negative ion of hydrogen, H−. Practically, the term hydride has two distinct but overlapping meanings. In the chemical vernacular the term hydride refers to a hydrogen atom that formally reacts as a hydrogen anion under common conditions as well as hydrogen atoms directly bonded to metal atoms regardless of their and written as H−), or as a positively-charged species H+. The latter cation An ion is an atom or molecule where the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge is written as though composed of a bare proton, but in reality, hydrogen cations in ionic compounds In chemistry, an ionic compound is a chemical compound in which ions are held together in a lattice structure by ionic bonds. Usually, the positively charged portion consists of metal cations and the negatively charged portion is an anion or polyatomic ion. Ions in ionic compounds are held together by the electrostatic force between oppositely always occur as more complex species. Hydrogen forms compounds with most elements and is present in water Water is the ubiquitous chemical substance, composed of hydrogen and oxygen, that is essential for the survival of many known forms of life. In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71% of the Earth's surface. On Earth, it and most organic compounds An organic compound is any member of a large class of chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of compounds such as carbonates, simple oxides of carbon and cyanides, as well as the allotropes of carbon, are considered inorganic. The division between "organic" and ". It plays a particularly important role in acid-base chemistry An acid-base reaction is a chemical reaction that occurs between an acid and a base. Several concepts that provide alternative definitions for the reaction mechanisms involved and their application in solving related problems exist. Despite several differences in definitions, their importance becomes apparent as different methods of analysis when with many reactions exchanging protons between soluble molecules. As the only neutral atom with an analytic solution to the Schrödinger equation In physics, especially quantum mechanics, the Schrödinger equation is an equation that describes how the quantum state of a physical system changes in time. It is as central to quantum mechanics as Newton's laws are to classical mechanics, the study of the energetics and bonding of the hydrogen atom played a key role in the development of quantum mechanics Quantum mechanics is a set of principles describing physical reality at the atomic level of matter (molecules and atoms) and the subatomic (electrons, protons, and even smaller particles). These descriptions include the simultaneous wave-like and particle-like behavior of both matter and radiation ("wave–particle duality"). In addition,.
Hydrogen is important in metallurgy Metallurgy is a domain of materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their mixtures, which are called alloys. It is also the technology of metals: the way in which science is applied to their practical use. Metallurgy is commonly used in the craft of metalworking as it can embrittle Hydrogen embrittlement is the process by which various metals, most importantly high-strength steel, become brittle and crack following exposure to hydrogen. Hydrogen cracking can pose an engineering problem especially in the context of a hydrogen economy. However, commercially workable and safe technology exists globally in the hydrogen industry, many metals,[5] complicating the design of pipelines and storage tanks.[6] Hydrogen is highly soluble in many rare earth As defined by IUPAC, rare earth elements or rare earth metals are a collection of seventeen chemical elements in the periodic table, namely scandium, yttrium, and the fifteen lanthanoids. Scandium and yttrium are considered rare earths since they tend to occur in the same ore deposits as the lanthanoids and exhibit similar chemical properties and transition metals The first definition is simple and has traditionally been used. However, many interesting properties of the transition elements as a group are the result of their partly filled d subshells. Periodic trends in the d-block are less prevailing than in the rest of the periodic table. Going across a period, the valence doesn't change, so the electron[7] and is soluble in both nanocrystalline and amorphous metals An amorphous metal is a metallic material with a disordered atomic-scale structure. In contrast to most metals, which are crystalline and therefore have a highly ordered arrangement of atoms, amorphous alloys are non-crystalline. Materials in which such a disordered structure is produced directly from the liquid state during cooling are called &.[8] Hydrogen solubility Solubility is the property of a solid, liquid, or gaseous chemical substance called solute to dissolve in a liquid solvent to form a homogeneous solution. The solubility of a substance strongly depends on the used solvent as well as on temperature and pressure. The extent of the solubility of a substance in a specific solvent is measured as the in metals is influenced by local distortions or impurities in the crystal lattice In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. A crystal structure is composed of a motif, a set of atoms arranged in a particular way, and a lattice. Motifs are located upon the points of a lattice, which is an array of points repeating periodically in three dimensions. The points can be.[9]
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But Mr. Burns, who was the company's longtime champion of electric and hydrogen fuel-cell vehicles, is retiring effective Oct. 1, to be replaced by a man he ...
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ue, 21 Jul 2009 15:58:31 GM
Italian scientists in Florence have discovered a method to produce . hydrogen. using water under 1000 atmospheres of pressure plus laser beams.
Q. Here's an interesting chemistry question... When using hydrogen in an internal combustion engine, it has a tendency to pre-ignite due to a hot intake valve, and although there are things that can be done to the engine itself to fix that, such as ceramic coating the valves or adding sodium filled valves, I was wondering what could be added to the hydrogen gas itself to counteract the pre-ignition tendency? Possibly another gas mixed in? Would an alcohol spray have any effect if mixed in with it like it does with gasoline? Ann, they tried this on mythbusters. A car battery doesn't have enough power to effectively perform electrolysis to split water molecules. Also Ann, the idea is to use hydrogen as the dominant fuel source, not as a… [cont.]
Asked by fieroturbo - Fri Dec 7 21:59:51 2007 - - 2 Answers - 0 Comments
A. gasoline is already being used by a company called their systems looks like it may work and they say that the hydrogen can be directly produced from distilled water, thus no need for a pressurized tank
Answered by ann l - Fri Dec 7 22:38:42 2007
