Search results for "Hydrogen atom" - New World Encyclopedia

of a carbon atom that is bonded to a hydrogen atom and double-bonded to ... of four carbon atoms and one oxygen atom. Hydroxyl (-OH) groups are ...

of just the elements carbon (C) and hydrogen (H). Each hydrocarbon molecule ... is a special case and can have only one hydrogen atom attached to it. ...

of a carbon atom that is bonded to a hydrogen atom and double-bonded to ... oxygen) has attached to it the fifth carbon atom and a hydroxyl group. ...

group, consists of a carbon atom bonded to a hydrogen atom with a single covalent bond and an oxygen atom with a double bond. Thus the chemical formula ...

As an example, the size of a hydrogen atom is estimated to be approximately ... The simplest atom is the hydrogen atom, which has atomic number 1 ...

in a hydrogen molecule (H2), each hydrogen atom takes part in the sharing ... held together by covalent bonds, with a hydrogen atom attached to each carbon ...

In DNA, cytosine (C) and thymine (T) form hydrogen bonds with their ... of atoms substituted in place of a hydrogen atom on the parent chain of ...

a carbonyl group (C=O) linked to a nitrogen atom (N), or a compound that contains ... Compounds in which a hydrogen atom on nitrogen from ammonia or an ...

The carbon atom adjacent to a carbonyl group is called the α-carbon ... group. Oxo also refers to a single oxygen atom coordinated to a transition ...

The atomic mass (ma) is the mass of a single atom, when the atom is ... is approximately equal to the mass of a hydrogen atom, a proton, or a neutron. ...

a proton, all amphiprotic substances contain a hydrogen atom. ... A common example of an amphiprotic substance is the hydrogen carbonate ...

force that exists between a hydrogen atom on one molecule and an ... one part of the bond involves a hydrogen atom, which is covalently ...

The synthesis of ammonia from nitrogen and hydrogen by the Haber process ... in the most complicated molecule first. Hydrogen, oxygen, and elements that ...

helium and three times that of liquid hydrogen (on a per unit volume basis ... *20Ne (90.48%), with 10 neutrons in the nucleus of each atom; ...

The nucleus of an atom is the very dense region at the center of the ... to refer to the "central point of an atom." The modern atomic meaning ...

nuclei. The most common isotope of the hydrogen atom is a single proton. The ... In chemistry and biochemistry, the proton is thought of as the hydrogen ...

tiny atomic nucleus. The nucleus of the hydrogen atom was found to be a proton ... behavior, as shown below in the example of the hydrogen atom.) ...

indicates that the sugar lacks an oxygen atom present in ribose, the parent ... in which an organic group replaces a hydrogen atom or multiple hydrogens ...

an ether functional group—an oxygen atom directly bound to two hydrocarbon ... the two alkyl groups attached to the oxygen atom (of the ether) and to append ...

" showing oxygen, helium, and hydrogen ions that gush into space ... charge. For example, H+ represents a hydrogen atom with a single positive ...

pure substance consists of only one type of atom. The older definition, while ... The atomic number of an element or atom, Z, is equal to the number ...

This oxygen atom is bonded to a hydrogen atom forming an OH (hydroxide) group in the clay structure. Clays can be categorized according to the ...

group that contain nitrogen as the key atom. Structurally amines resemble ... due to the absence of a replaceable hydrogen atom. With the much less active ...

guanine. In DNA, adenine and guanine form hydrogen bonds with their complementary ... These hydrogen bonding modes are for classical Watson-Crick base pairing ...

6 and form stable complexes in the gas phase. Hydrogen-bonds are formed between the three hydrogen atoms of protonated amines and three oxygen atoms ...

acids, written as R-COOH, where R is a hydrogen atom or an alkyl group. Compounds ... to be less stable, and causing the hydrogen atom to be labile, thus it ...

In chemistry, esters are organic compounds in which an organic group (symbolized by R' in this article) replaces the hydrogen atom of a ...

dioxide, or the reduction of carbon by hydrogen to yield methane (CH4), ... *Oxidation describes the loss of electrons by a molecule, atom or ion. ...

an atom with a single electron, such as the hydrogen atom. ... In atoms with a single electron (essentially the hydrogen atom), the ...

in a volume 1/100,000 the size of the atom. He pioneered the orbital ... that led him to the Rutherford model of the atom, having a very small positively ...

(as the carbons are fully “saturated” with hydrogen atoms) ... of the carbon atoms, bonded to only one hydrogen atom, forms a double bond ...

to the lack of an acidic proton (that is, a hydrogen atom directly bonded to an electronegative atom such as fluorine, oxygen, or nitrogen). Ethyl acetate ...

electrophile through its terminal nitrogen atom with an activated double bond. ... * Reduction with hypophosphorous acid replaces the nitrogen by hydrogen ...

element as "an element whose atom has an incomplete d sub-shell ... involving the reaction of nitrogen and hydrogen to produce ammonia. Nickel ...

are roughly multiples of the weight of the hydrogen atom. were simple integral multiples of that of hydrogen. To test this hypothesis ...

of silicon atoms covalently bound to hydrogen atoms. The general formula ... silane decomposes into silicon and hydrogen. It can therefore be used ...

low toxicity, but some specialized boron hydrogen compounds are toxic and ... reducing volatile boron halogenides with hydrogen at high temperatures. Highly ...

element can be reduced to its basic unit, the atom, which has a specific weight for each element. Based on this idea, in 1828 he compiled a table of ...

did not discriminate as to which hydrogen atom they would react to. ... found that they all consisted of a carbon atom surrounded by atoms of more ...

as "the ability of an atom in a molecule to attract electrons ... cases) when one electron is added to an atom of that element. Ionization ...

the development of the vortex theory of the atom proposed by William Thomson ... mass of the electron compared to the hydrogen atom. Then, in 1899, he measured ...

Note that the position of the oxygen atom differs between the two: ... carbons rather than to one carbon and one hydrogen. As it lacks a hydroxyl ...

In DNA, thymine and cytosine form hydrogen bonds with their complementary ... of atoms substituted in place of a hydrogen atom on the parent chain of ...

Thomson was the first indication that the atom had internal structure. At ... That is, electrons were ejected from the atom with a range of energies, ...

roughly twice the mass of an ordinary hydrogen atom, and deuterium is also ... is the second isotope after ordinary (or light) hydrogen. ...

compound of argon with fluorine and hydrogen—was first reported by researchers ... electronic structure of their atoms. The atom of each of these elements ...

megaparsec per year or roughly one hydrogen atom per cubic meter per billion ... amount of lithium, as well as regular hydrogen, since no mechanism of nucleosynthesis ...

and negatively charged electrons in an atom, the ions (some positively ... Main article: Atom. Atoms are the fundamental units of chemistry as ...

The non-hydrogen atoms of functional groups are always associated ... The first carbon atom after the carbon that attaches to the functional ...

comprises a carbon atom bonded to a hydrogen atom and double-bonded to ... indicates that the sugar lacks an oxygen atom present in ribose, the parent ...

there is a double bond between a carbon atom and an oxygen atom. On the ... reaction evolves potentially hazardous hydrogen chloride gas. For medical ...

sulfuric acid at 50 - 60 °C, where one hydrogen atom is displaced to give ... Now a mixture of hydrogen gas and nitrobenzene vapors are heated at ...

) is a radioactive isotope of hydrogen. The nucleus of tritium (sometimes ... 1934 from deuterium, another isotope of hydrogen, by Ernest Rutherford, working ...

different electronegativity—one atom attracts electrons more than ... * Hydrogen cyanide: 2.98 * Cyanamide: 4.27 * Potassium bromide: 10.41 ...

Organic compounds are primarily composed of carbon and hydrogen, and ... and carboxylic acids where there is hydrogen bonding present. Organic ...

bound for the same reason that the helium atom is inert: Each pair of protons ... ]] + [[Hydrogen-2| hydrogen|2 ]] → 2 [[Helium| helium|4 ...

the second dissociation, HPO42–, is the hydrogen phosphate anion. The anion ... Note that each extra phosphoric unit adds 1 extra H (hydrogen) atom ...

png|center|thumb|280px|The first few hydrogen atom electron orbitals shown ... In 1925 Bohr's model of the atom was superseded by the wave ...

should stick together tightly. A hydrogen atom should be 100,000 times ... a postage stamp depicting Bohr, the hydrogen atom and the formula for the ...

H2SO4. The acid dissociates producing hydrogen ions, H+. A hydrogen ion ... A nucleophilic oxygen atom of unprotonated ethanol displaces a water ...

which Davy proved the lack of oxygen in hydrogen sulfide (H2S), hydrogen ... shift from oxygen-based acids to hydrogen-based acids, started by ...

*Atom Transfer Radical Polymerization ([[ATRP (chemistry)| ... Reactive oxygen species or ROS are species such as superoxide, hydrogen ...

four carbon atoms, including the carbon atom in the carboxyl group. The ... is made up of four carbon atoms and ten hydrogen atoms, so their common molecular ...

produced by reducing tungsten oxide with hydrogen or carbon. ... of 6.4 minutes). (A metastable state of an atom is an unstable state in which ...

The combustion of hydrogen sulfide and organosulfur compounds proceeds ... In terms of electron-counting formalisms, the sulfur atom has an oxidation ...

the correct energy eigenvalues for the hydrogen-like atom. This paper has ... development of science was to describe the atom in terms of the wave and particle ...

group in the benzene ring is replaced by a nitrogen atom. Pyridine has a lone pair of electrons at the nitrogen atom. Because ...

an "acyl" group replaces a hydrogen atom on the benzene ring. ... an "alkyl" group replaces a hydrogen atom on the benzene ring ...

it has an electronegativity of 3.0. Each atom of nitrogen has five electrons ... where R2 or R3 or both may represent a hydrogen atom (each). A peptide or ...

number of protons in the nucleus of each atom) is 6. Each carbon atom is ... (six-membered) rings in which each carbon atom is bonded to three other atoms ...

halogenation. In this reaction a hydrogen atom is removed from the alkane ... one with the halogen and one with the hydrogen atom of the hydrohalic acid ...

group (-N=C=S) replaces a hydrogen atom on the bottom ring of the fluorescein molecule. This derivative is reactive towards amine groups on proteins ...

halogen) atoms attached to a central carbon atom. For this reason, it is placed ... chloral hydrate. Some of the aldehyde hydrogen is retained in the product ...

it with water. The reaction produced hydrogen and sodium hydroxide—two ... chlorine in the anode compartment and hydrogen and sodium hydroxide in ...

sufficiently strong that it will remove hydrogen and oxygen atoms from other ... where protonation occurs on an oxygen atom, is important in many reactions ...

indicates that the sugar lacks an oxygen atom present in ribose, the parent ... in which an organic group replaces a hydrogen atom or multiple hydrogens ...

down to fractions of the size of an atom. In our universe, the short ... down to fractions of the size of an atom. Electromagnetic energy at ...

Group 1 of the periodic table (excluding hydrogen in all but one rare circumstance ... vigorous reactions with water to liberate hydrogen gas. These reactions also ...

Waals was able to estimate the size of a hydrogen molecule. ... * Atom * Gas * Heike Kamerlingh Onnes * Hydrogen * Molecule ...

sulfur, but with a methyl group instead of hydrogen. This methyl group (one carbon and three hydrogen, or CH3) can be activated, and is used in many ...

family of chemical compounds of silicon, hydrogen, and oxygen) forms the basis ... made of silicon, oxygen, carbon, germanium, and hydrogen. ...

and resistance-sintering in a vacuum or hydrogen atmosphere. This procedure ... from APR simply by reducing the latter with hydrogen. * Perrhenic acid ...

Traditional atomism, derived from the word atom, is used in two distinct ... "uncuttable." Whereas the modern atom is indeed divisible, it is ...

to very short gamma rays smaller than atom nuclei. Frequency is inversely ... As a photon is absorbed by an atom, it excites an electron, elevating ...

if all four substituents on the central atom are different, the molecule ... center carbon atom. Sighting with the hydrogen atom away from the viewer ...

in our galaxy is estimated at 1 hydrogen atom/cm3.Wynn-Williams (1992), 38. are small quantities of matter (mostly hydrogen), cosmic dust and cosmic ...

| Hydrogen (H2) | 4,124 | 24,660 |- | Methane (CH4) | 518.3 | 3,099 |- | Nitrogen (N2) | 296.8 | 1,775 |- | Oxygen (O2) | 259.8 | 1,554 ...

with the three methyl groups replaced by hydrogen atoms. === Chemical reactions === Camphor can undergo various reactions, some of which are given ...

quot; which can be viewed as derived from hydrogen persulfide, H2S2. Thus pyrite ... assigns formal oxidation states to each atom, pyrite is probably best described ...

and a proton form a normal matter hydrogen atom. Although the basic principles ... became a reality in the early 1990s. An atom of antihydrogen is composed ...

groups. A carboxyl group comprises a carbon atom attached to an oxygen atom ... a mixture of tartaric acid and potassium hydrogen sulfate, or by the hydrolysis ...

of the electron and the structure of the atom. == Early life == ... and chlorine by substituting chlorine for hydrogen in ethylene. He then took ...

be handled with care. For instance, hydrogen sulfide is quite toxic, ... to the odor of sulfur compounds such as hydrogen sulfide, which has the smell ...

engines. It consists of one carbon atom covalently bonded to one oxygen ... dipole moment with its negative end on the carbon atom. ...

as a result of the nuclear fusion of hydrogen in stars. On Earth, it is ... element in the known universe, after hydrogen, constituting 23 percent ...

it splits into a molecule of O2 and an atom of oxygen. These processes ... A single chlorine atom could keep on destroying ozone for up to two ...

hydroxyl group (OH) attached to each carbon atom. To indicate this arrangement ... It could also be used to produce hydrogen gas or citric acid. ...

succeeded in decomposing water into hydrogen and oxygen by electrolysis ... Daniell invented a primary cell in which hydrogen was eliminated in the generation ...

component) that contained one less hydrogen atom than the molecule being ... hydrocarbons with 0, 2, 4, 6, and 8 fewer hydrogen atoms (per molecule) than ...

principle (e.g. the electron orbiting a hydrogen atom has the probability, albeit small, that it could be anywhere else in the universe at any ...

Ammonia is a chemical compound of nitrogen and hydrogen, with the ... of nitrous acid and nitrites with hydrogen. Additionally, it was produced ...

a complex chemical process in which hydrogen is used to reduce ammonium ... are versatile catalysts. For instance, hydrogen sulfide (H2S) can be split ...

structure stabilized by numerous hydrogen bonds. Tropocollagen subunits ... side group than glycine’s single hydrogen atom. For the same reason ...

Radioactive decay results in an atom of one type, called the parent ... the universe began as a mixture of hydrogen-1 (75 percent) and helium ...

a low density of particles, predominantly hydrogen plasma, as well as electromagnetic ... the Universe as the equivalent of one hydrogen atom per cubic meter ...

Boyle had unknowingly prepared both hydrogen and nitric oxide gases as ... example of gas in chemical warfare is hydrogen cyanide (HCN), infamously ...

to be made mostly of ice—that is, hydrogen compounds. ... first effective working model of the hydrogen atom resembled a simplified ...

with species other than oxygen as the hydrogen abstractor) are involved ... molecule into a methyl radical and a hydrogen atom. When two methyl radicals ...

which is positively charged), together forming a hydrogen atom, is about 40 orders of magnitude stronger than the gravitational force acting between them. ...

enough energy to actually split a heavier atom into two light element fragments ... developing Bohr's theory of the hydrogen atom. If this sounds like ...

| Hydrogen peroxide || 128 aq–60(−30–25 °C) |- | Hydrocyanic acid || 158.0–2.3(0–21 °C) |- | Titanium dioxide || 86–173 ...

molecule generally contains carbon, hydrogen, and oxygen, usually in ... conditions). The third is a simple hydrogen atom. The fourth is commonly ...

made up of chemical elements other than hydrogen and helium—is 13 time ... small rocky core, surrounded by metallic hydrogen, with further layers of ...

with chlorine and oxygen and displaces hydrogen from dilute acids. It is ... it releases severely irritating fumes of hydrogen chloride. It forms a white ...

with the replacement of chlorine with hydrogen on the biphenyl skeleton ... the resulting aryl radical extracts a hydrogen atom from the solvent, or ...

the neutron to explain for isotopes of hydrogen. This particle was believed ... * Atom * Enrico Fermi * Ernest Rutherford * Manhattan Project ...

Each molecule of water consists of two hydrogen atoms covalently bonded ... partial positive charge (δ+) near each hydrogen atom. Thus the entire molecule ...

process, including the removal of smell (hydrogen sulfide remediation), taste ... quot; of oxygen which readily gives up one atom of oxygen providing a powerful ...

The hydrogen (H) atom in the carboxyl group (−COOH) in carboxylic ... shows that the molecules pair up into dimers connected by hydrogen ...

is likely to undergo nuclear fission. The atom splits into two or more smaller ... experimental technology, generally with hydrogen as fuel. While not currently ...

==Mass-energy equivalence: Sunlight and atom bombs== energy. This is the basic principle behind atom bombs and production of energy ...

derivatives of fullerenes. For example, hydrogen atoms, halogen atoms, or ... and twelve pentagons, with a carbon atom at the vertices of each polygon ...

core at the center, a liquid metallic hydrogen layer above that, and a ... onto the rings, it would be on the order of one atom thick. ...

It has a permanent dipole moment (the O atom end is electron rich, and ... in the atmosphere and is split into hydrogen and oxygen by ultraviolet ...

further, which included oxygen, nitrogen, hydrogen, phosphorus, mercury, zinc ... the mass and all the positive charge of the atom resided. The nuclear charge ...

by their experiments that a group of carbon, hydrogen, and oxygen atoms called the "benzoyl" radical can behave like an element, take ...

groups that contain a basic nitrogen atom with a lone pair.) Choline ... methyl groups (a carbon attached to three hydrogen atoms) for methylation reactions ...

mechanical analyses of bonding in the hydrogen molecule, done by Walter ... orbitals and analyzed the tetravalency of the carbon atom. ...

mantle), rutile (titanium dioxide), and ice (hydrogen oxide). The oxide class includes the hydroxide minerals. === Sulfide class === ...

estimated to be equivalent to about one hydrogen atom per cubic meter of space ... seen with radio frequency observations of hydrogen. Based on rotation profiles ...

matter, as in the Bohr model of the hydrogen atom (shown here). Although ... agreed excellently with the spectrum of hydrogen, but not with those of other ...

in the understanding of the physics of the atom occurred which resulted both ... Ernest Walton were first to "split the atom" (cause a nuclear reaction ...

aluminum is heated at 1500 °C in an atmosphere of hydrogen. ... from trimethylaluminum and an excess of hydrogen. It burns explosively in ...

interstellar space, where there are a few hydrogen atoms per cubic centimeter ... can ever have an exact position. Each atom exists as a probability function ...

weapon based on nuclear fusion—the hydrogen bomb—Oppenheimer initially ... known as the Teller-Ulam design for a hydrogen bomb. This new design seemed ...

Graphene is a one-atom-thick planar sheet of carbon atoms that are ... One can then hope to fool Nature and extract single-atom-thick crystallites ...

crystal structure of sodium chloride. Each atom has six nearest neighbors ... chlorine, this chloralkali process yields hydrogen gas and sodium hydroxide ...

of the stars in our Galaxy. After the hydrogen-fusing lifetime of a main ... regions occupied by electrons bound to an atom—would normally allow. Eddington ...

found apparent stimulated emission in hydrogen spectra and made the first ... of atoms in a coherent state can be called an atom laser. ...

bullet was developed to shoot at hydrogen-filled Zeppelins over Britain ... membered rings that are interlinked. Each atom is bonded to three other atoms ...

gas of average density less than one atom per cubic meter. Most galaxies ... of 21 cm resulting from interstellar atomic hydrogen gas; ...

** Hydrogen fuel ** Lightening ** Nuclear energy ==Solar== ... from carbon monoxide, carbon dioxide, and hydrogen. However, methanol also ...

to air. It reacts with water, displacing hydrogen and forming calcium hydroxide ... In terms of the electronic configuration of each neutral atom, the ...

was the high-volume production of hydrogen gas. He also held several ... sink for chlorofluoromethanes: chlorine atom-catalysed destruction of ozone ...

contaminants, in particular thiols and hydrogen sulfide, must be removed ... is higher than for gasoline (higher hydrogen to carbon ratio). The weight ...

it reacts with dilute acids to release hydrogen. The one common oxidation ... element is "an element whose atom has an incomplete d sub-shell ...

(electrons on the outermost shell of an atom) of matter, while wavelengths ... sunlight and artificial light. A burning hydrogen flame, for instance, radiates ...

first cooled sufficiently to form neutral hydrogen, allowing space to become ... universe began as a simple "primeval atom," perhaps echoing previous ...

|Tetrahydrobiopterin Thony et al. (2000). || Oxygen atom and electrons ... * Warburg, O., and W. Christian. 1936. Pyridin, the hydrogen-transferring ...

weight per electron, mH is the mass of the hydrogen atom, and ω30≈2.018236 is a constant connected with the solution to the Lane-Emden equation. ...

space. Almost all elements heavier than hydrogen and helium were created ... cloud of material composed primarily of hydrogen, along with helium and trace ...

less abstract and is the way the atom is viewed these days. Both ... the discovery of the allotropic forms of hydrogen" . ...

of neutrons released by a fissioning atom of uranium-235 must impact ... for that state. Ions of U3+liberate hydrogen from water and are therefore ...

png|thumb|left|200px|The first few hydrogen atom electron orbitals shown ... Water is a stable chemical substance that is composed of one oxygen ...

# As a byproduct in ammonia and hydrogen plants, where methane is ... of water molecules, while the hydrogen is split into its protons ...

in nature. In fact, 244Pu is the heaviest atom naturally occurring in traces ... compared to another method: when a U-235 atom captures a neutron, it is ...

The DNA double helix is stabilized by hydrogen bonds between the bases ... At top, a GC base pair with three hydrogen bonds. At the bottom, AT ...

that were key to development of both the Atom and Hydrogen bombs, and finally to his work developing computers. Von Neumann's work culminated ...

with a hydroxyl group that can donate a hydrogen atom to reduce free radicals ... three stereocenters were changed (so the hydrogen was now pointing down and ...

is more free to move and is not bound to an atom or molecule. ... fountain" shows oxygen, helium, and hydrogen ions gushing into space ...

career: Studying the diffusion of hydrogen through heated platinum. He soon transferred to theoretical physics. In 1877, he went to Berlin for ...

can be conceptualized by wrapping a one-atom-thick layer of graphite called ... of oxides solid solutions in methane and hydrogen. ===Fullerite=== ...

Meanwhile, Kennan opposed the building of the hydrogen bomb, and the ... * Russia, the Atom, and the West (1958) * Russia and the West under ...

energy and once again become bound to an atom within the solar cell without ... enhanced (PE-CVD)) from silane gas and hydrogen gas. Depending on the deposition ...