Many chemical properties of astatine have been determined using tracer studies on extremely dilute astatine solutions.

They were used in 18th-century chemical studies for burning materials in closed glass vessels where the products of combustion could be trapped for analysis.

Biochemistry studies the chemical properties of important biological molecules, like proteins, and in particular the chemistry of enzyme-catalyzed reactions.

In particular, chemistry studies interactions between atoms, and chemical bond s.

Energy and entropy considerations are invariably important in almost all chemical studies.

One of the first studies of condensed states of matter was by English chemist Humphry Davy, when he observed that of the forty chemical elements known at the time, twenty-six had metallic properties such as lustre, ductility and high electrical and thermal conductivity.

*** A biological science – one that studies the role of chemicals and chemical processes in living organisms.

* Thermochemistry – The branch of chemistry that studies the relation between chemical action and the amount of heat absorbed or generated.

Electrochemistry is a branch of chemistry that studies chemical reactions which take place in a solution at the interface of an electron conductor ( a metal or a semiconductor ) and an ionic conductor ( the electrolyte ), and which involve electron transfer between the electrode and the electrolyte or species in solution.

Early animal studies received attention in the media, and some doctors began controversially using the chemical off-label.

These studies explain the chemical changes associated with the major seismic discontinuities in the mantle, and show the crystallographic structures expected in the inner core of the Earth.

Cayley linked his results on trees with the contemporary studies of chemical composition.

Many products are advertised as " herbal viagra " or " natural " sexual enhancement products, but no clinical trials or scientific studies support the effectiveness of these products for the treatment of erectile dysfunction, and synthetic chemical compounds similar to sildenafil have been found as adulterants in many of these products.

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.

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 uses techniques from chemical mineralogy, especially isotopic studies, to determine such things as growth forms in living plants and animals as well as things like the original mineral content of fossils.

Clinical Medicine and Pathophysiology: pathophysiology with emphasis on the principal physiological systems, clinical medicine, differential diagnosis, clinical correlation and case studies, chemical dependency, chronic pain management ;

The science of extractive metallurgy is a specialized area in the science of metallurgy that studies the extraction of valuable metals from their ores, especially through chemical or mechanical means.

Because of its instability, chemical studies of promethium are incomplete.

In vitro studies of purified proteins in controlled environments are useful for learning how a protein carries out its function: for example, enzyme kinetics studies explore the chemical mechanism of an enzyme's catalytic activity and its relative affinity for various possible substrate molecules.

* ( 2004 ): Piper: A model genus for studies of evolution, chemical ecology, and trophic interactions.

* In reactions, quantum chemistry studies the ground state of individual atoms and molecules, the excited states, and the transition states that occur during chemical reactions.

* On the calculations: quantum chemical studies use also semi-empirical and other methods based on quantum mechanical principles, and deal with time dependent problems.

In this publication measurements of interfacial angles of crystals are used to classify and identify chemical substances.

The chief factors responsible for the spoilage of fresh foodstuffs are ( 1 ) microorganisms such as bacteria, molds, and yeasts, ( 2 ) enzymes, ( 3 ) insects, ( 4 ) sprouting, and ( 5 ) chemical reactions.

No chemical fertilizers and poisonous insecticides and fungicides are used ''.

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 ).

Modern definitions are concerned with the fundamental chemical reactions common to all acids.

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.

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.

Actinium has similar chemical properties as lanthanum and other lanthanides, and therefore these elements are difficult to separate when extracting from uranium ores.

" While chemical issues in the brain that result in anxiety ( especially resulting from genetics ) are well documented, this study highlights an additional environmental factor that may result from being raised by parents suffering from chronic anxiety.

The chemical structures of the 22 standard amino acids, along with their chemical properties, are described more fully in the article on these proteinogenic amino acids.

Its chemical and physical properties are so similar to that of natural amethyst that it can not be differentiated with absolute certainty without advanced gemnological testing ( which is often cost-prohibitive ).

There are five classes of amber, defined on the basis of their chemical constituents.

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.

Using the Debye model, the specific heat and entropy of a pure crystal are proportional to T < sup > 3 </ sup >, while the enthalpy and chemical potential are proportional to T < sup > 4 </ sup >.

A key concept in thermodynamics, many rapid chemical and physical processes are described or approximated in this way.

Compounds that are still isolated from living organisms are the aminoglycosides, whereas other antibacterials — for example, the sulfonamides, the quinolones, and the oxazolidinones — are produced solely by chemical synthesis.

A number of harmful and undesired ( adverse ) effects have been observed, including lowered life expectancy, extrapyramidal effects on motor control – including akathisia ( an inability to sit still ), trembling, and muscle weakness – weight gain, decrease in brain volume ( although this is being debated, since schizophrenia, which is often treated with antipsychotics, also causes a shrinkage of brain volume ), enlarged breasts ( gynecomastia ) in men and milk discharge in men and women ( galactorrhea due to hyperprolactinaemia ), lowered white blood cell count ( agranulocytosis ), involuntary repetitive body movements ( tardive dyskinesia ), diabetes, sexual dysfunction, a return of psychosis requiring increasing the dosage due to cells producing more neurochemicals to compensate for the drugs ( tardive psychosis ), and a potential for permanent chemical dependence leading to psychosis worse than before treatment began, if the drug dosage is ever lowered or stopped ( tardive dysphrenia ).

In most cases of interest in chemical thermodynamics there are internal degrees of freedom and processes, such as chemical reactions and phase transitions, which always create entropy unless they are at equilibrium, or are maintained at a " running equilibrium " through " quasi-static " changes by being coupled to constraining devices, such as pistons or electrodes, to deliver and receive external work.

The symbol of fire was a cue pointing towards transformation, the chemical variant being the symbol delta, which is also the classical symbol for fire.

In the case of enantiomers, these have no chemical or physical differences apart from being three-dimensional mirror images.

The cathode can be negative as when the cell is electrolytic ( where electrical energy provided to the cell is being used to decompose chemical compounds ); or positive as when the cell is galvanic ( where chemical reactions are used to generate electrical energy ).

Confirmed use of biological warfare by a nation state has not occurred since 1945, and chemical warfare has been used only a few times ( the latest known confrontation in which it was utilized being the Iran-Iraq War ).

The fuel cell can turn the chemical energy bound in hydrocarbon gases or hydrogen directly into electrical energy with much higher efficiency than any combustion process ; such devices have powered many spacecraft and are being applied to grid energy storage for the public power system.

Many chemical pickling processes also involve heating or boiling so that the food being preserved becomes saturated with the pickling agent.

Lewis later cited these notes in his classic 1916 paper on chemical bonding, as being the first expression of his ideas.

Increased levels of this chemical are detected in the blood if red cells are being destroyed more rapidly than usual.

By sorting formulas according to the number of atoms of each element present in the formula according to these rules, with differences in earlier elements or numbers being treated as more significant than differences in any later element or number — like sorting text strings into lexicographical order — it is possible to collate chemical formulas into what is known as Hill system order.

Jean was able, through telepathic therapy with the comatose Jessica Jones, to grant Jessica immunity to the Purple Man's mind control abilities, despite his powers being chemical in nature rather than psychic.

These gauges are accurate from 10 Torr to 10 < sup >− 3 </ sup > Torr, but they are sensitive to the chemical composition of the gases being measured.

Ionization gauge calibration is very sensitive to construction geometry, chemical composition of gases being measured, corrosion and surface deposits.

Psilocybin, a naturally occurring chemical in certain psychedelic mushrooms such as Psilocybe cubensis, is being studied for its ability to help people suffering from psychological disorders, such as obsessive-compulsive disorder.

Its relative rarity on Earth, like that of helium, is due to its relative lightness, high vapor pressure at very low temperatures, and chemical inertness, all properties which tend to keep it from being trapped in the condensing gas and dust clouds which resulted in the formation of smaller and warmer solid planets like Earth.

Additionally, there have been a few incidents of chemical weapons washing ashore or being accidentally retrieved, for example during dredging or trawl fishing operations.

It sometimes contains a significant amount of ethane, propane, butane, and pentane — heavier hydrocarbons removed for commercial use prior to the methane being sold as a consumer fuel or chemical plant feedstock.

Potassium metal has only a few special applications, being replaced in most chemical reactions with sodium metal.

It is notable for being the only element besides technetium all of whose isotopes are radioactive but which is followed in the periodic table by chemical elements with stable isotopes.

* A chemical ( typically a solvent ) can be sprayed along with the paint to dissolve together both the delivered paint and the chemicals on the surface of the object being painted ;