Alkanes ( also known as paraffins or saturated hydrocarbons ) are chemical compounds that consist only of hydrogen and carbon atoms and are bonded exclusively by single bonds ( i. e., they are saturated compounds ) without any cycles ( or loops ; i. e., cyclic structure ).

Although the neutral ground-state chemical compounds of argon are presently limited to HArF, argon can form clathrates with water when atoms of it are trapped in a lattice of the water molecules.

They had determined that nitrogen produced from chemical compounds was one-half percent lighter than nitrogen from the atmosphere.

As with most lanthanides and actinides, actinium assumes oxidation state + 3 in nearly all its chemical compounds.

He proposed that each element consists of atoms of a single, unique type, and that these atoms can join together to form chemical compounds.

In accordance with this, many antibacterial compounds are classified on the basis of chemical / biosynthetic origin into natural, semisynthetic, and synthetic.

This text clarified the concept of an element as a substance that could not be broken down by any known method of chemical analysis, and presented Lavoisier's theory of the formation of chemical compounds from elements.

Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms.

* Chemical affinity, the willingness of two or more elements or compounds to form a chemical or attractive bond of some type

The Ames test is a biological assay to assess the mutagenic potential of chemical compounds.

At high temperatures, organobromine compounds are easily converted to free bromine atoms, a process which acts to terminate free radical chemical chain reactions.

This gradual transformation is an important consideration when studying the properties of elemental berkelium and its chemical compounds, since the formation of californium brings not only chemical contamination, but also self-radiation damage, and self-heating from the emitted alpha particles.

Strictly speaking, a mixture of compounds, elements or compounds and elements is not a chemical substance, but it may be called a chemical.

Generally it refers to a system for naming chemical compounds.

However, today the IUPAC system of chemical nomenclature allows chemists to specify by name specific compounds amongst the vast variety of possible chemicals.

However, not all substances or chemical compounds consist of discrete molecules, and indeed most of the solid substances that makes up the solid crust, mantle, and core of the Earth are chemical compounds without molecules.

Though they saw the old-style chemical rockets lift up from the field beyond B'dikkat's cabin, they did not make plans to hide among the frozen crop of transmuted flesh.

The alkali metals are a group of chemical elements in the periodic table with very similar properties: they are all shiny, soft, silvery, highly reactive metals at standard temperature and pressure and readily lose their outermost electron to form cations with charge + 1.

Experiments have been conducted to attempt the synthesis of ununennium ( Uue ), which is likely to be the next member of the group, but they have all met with failure .< ref name =" link "> However, ununennium may not be an alkali metal due to relativistic effects, which are predicted to have a large influence on the chemical properties of superheavy elements.

Argon ( αργος, Greek meaning " inactive ", in reference to its chemical inactivity ) was suspected to be present in air by Henry Cavendish in 1785 but was not isolated until 1894 by Lord Rayleigh and Sir William Ramsay in Scotland in an experiment in which they removed all of the oxygen, carbon dioxide, water and nitrogen from a sample of clean air.

Its chemical composition makes it difficult to match the amber to its producers – it is most similar to the resins produced by flowering plants ; however, there are no flowering plant fossils until the Cretaceous, and they were not common until the Upper Cretaceous.

Experimentally, it is found that all spontaneous processes ( including chemical reactions ) result in a decrease in G as they proceed toward equilibrium.

Making use of a variety of proprietary chemical processes, they produced colored beads that were sold around the globe.

In France, Santo Daime won a court case allowing them to use the tea in early 2005 ; however, they were not allowed an exception for religious purposes, but rather for the simple reason that they did not perform chemical extractions to end up with pure DMT and harmala and the plants used were not scheduled.

The mechanism of these types of antidepressants involves affecting the neurotransmitters used to communicate between brain cells ; they interfere with reuptake process of the specific chemical messengers.

Depending on the chemical composition of the adhesive, they will adhere to different materials to greater or lesser degrees.

This pharmaceutical coding system divides drugs into different groups according to the organ or system on which they act and / or their therapeutic and chemical characteristics.

Or are they chemical control — a socially-useful reduction of the paranoid, deluded, distressed, bizarre and odd into semi-vegetative zombies?

In June 2011, the Health Minister of Malaysia, Liow Tiong Lai, instructed companies selling " Strawberry Syrup ", a material used in some bubble teas, to stop selling them after chemical tests showed they were tainted with a carcinogen identified as DEHP.

In 1983, they repeated the experiment using a new technique: measurement of alpha decay from a descendant using chemical separation.

Though herbicides are chemicals, they are often grouped with biological warfare and chemical warfare because they may work in a similar manner as biotoxins or bioregulators and also because the Army Biological Laboratory tested them and the Army's Technical Escort Unit which all chemical, biological, radiological ( nuclear ) materials.

This means that the size, charge, and other chemical properties of the atoms and molecules attempting to cross it will determine whether they succeed in doing so.

The semiochemicals trigger the fungal organism to react in a specific manner, while if the same chemical molecules are not part of biotic messages, they do not trigger the fungal organism to react.

Thus, all carbon isotopes have nearly identical chemical properties because they all have six protons and six electrons, even though carbon atoms may differ in number of neutrons.

Amides undergo many chemical reactions, usually through an attack on the carbonyl breaking the carbonyl double bond and forming a tetrahedral intermediate.

Spraying was usually done either from helicopters or from low-flying C-123 Provider aircraft, fitted with sprayers and " MC-1 Hourglass " pump systems and chemical tanks.

All these advances in chemistry led to what is usually called the chemical revolution.

The interactions, reactions and transformations that are studied in chemistry are usually the result of interactions between atoms, leading to rearrangements of the chemical bonds which hold atoms together.

It can be symbolically depicted through a chemical equation, which usually involves atoms as subjects.

All but a few of the most inert elements, such as noble gases and noble metals, are usually found on Earth in chemically combined form, as chemical compounds.

One of the most convenient, and certainly the most traditional presentation of the elements, is in form of periodic table, which groups elements with similar chemical properties ( and usually also similar electronic structures ) together.

The number of neutrons in a nucleus usually has very little effect on an element's chemical properties ( except in the case of hydrogen and deuterium ).

Chemical reactions are usually characterized by a chemical change, and they yield one or more products, which usually have properties different from the reactants.

Though the fiber flow ( local inhomogeneities of the material's chemical composition generated during casting ) doesn ’ t follow the shape of the crankshaft ( which is undesirable ), this is usually not a problem since higher quality steels, which normally are difficult to forge, can be used.

Nonthermal motors usually are powered by a chemical reaction, but are not heat engines.

It is to be expected that the electronegativity of an element will vary with its chemical environment, but it is usually considered to be a transferable property, that is to say that similar values will be valid in a variety of situations.

This is usually done by " chemical experience ": in the above example, hydrogen bromide dissolves in water to form H < sup >+</ sup > and Br < sup >–</ sup > ions, so it may be assumed that bromine is more electronegative than hydrogen.

Once reaching the cathode, the ions are reunited with the electrons and the two react with a third chemical, usually oxygen, to create water or carbon dioxide.

However, the soda makes the glass water soluble, which is usually undesirable, so lime ( calcium oxide, generally obtained from limestone ), some magnesium oxide ( MgO ) and aluminium oxide ( Al < sub > 2 </ sub > O < sub > 3 </ sub >) are added to provide for a better chemical durability.

Hydrolysis usually means the cleavage of chemical bonds by the addition of water.

This field covers all chemical compounds except the myriad organic compounds ( carbon based compounds, usually containing C-H bonds ), which are the subjects of organic chemistry.

However, it is usually accompanied by physical or chemical changes that permanently degrade the material's insulating properties.

Lutetium usually occurs in association with the element yttrium and is sometimes used in metal alloys and as a catalyst in various chemical reactions.

These are usually organic chemical solvents, such as methanol, ethanol or ethylene glycol, to which are added chemical dyes such as coumarin, rhodamine, and fluorescein.

In biochemistry, ligase ( from the Latin verb ligāre — " to bind " or " to glue together ") is an enzyme that can catalyze the joining of two large molecules by forming a new chemical bond, usually with accompanying hydrolysis of a small chemical group dependent to one of the larger molecules or the enzyme catalyzing the linking together of two compounds .... e. g.: Enzymes which catalyze joining of C-O, C-S, C-N etc.