Actinium ( Ac ) has no stable isotopes, thus a standard atomic mass cannot be given.

Actinium also has two meta states.

Actinium gave the name to the actinide series, a group of 15 similar elements between actinium and lawrencium in the periodic table.

Actinium, which occurs only in trace amounts, continues the trend in chemical behavior for metals that form tripositive ions with a noble gas configuration ; synthetic lawrencium is calculated and partially shown to be more similar to lutetium and yttrium.

Actinium ( ) is a radioactive chemical element with symbol Ac and atomic number 89, which was discovered in 1899.

* Actinium, a chemical element

The actinide series are the second row of the f-block ( 5f series ) and comprise the elements from Actinium to Lawrencium.

< sup > 207 </ sup > Pb is the end of the Actinium series from < sup > 235 </ sup > U.

Actinium is found only in traces in uranium ores as the isotope < sup > 227 </ sup > Ac, which decays with a half-life of 21. 772 years, predominantly emitting beta particles.

Actinium is a soft, silvery-white, radioactive, metallic element.

Actinium reacts rapidly with oxygen and moisture in air forming a white coating of actinium oxide that prevents further oxidation.

Scandium, Yttrium, Elements des Terres Rares, Actinium, P. Pascal, Editor, Masson & Cie 1959

Receipt Date: 31-DEC-55 4358283-Retrieved 2012-01-29 see also: < sup > 228 </ sup > Ac = ( Actinium 228 ) In 1959, he joined the staff of CERN ( European Organization for Nuclear Research ) in Geneva.

* Actinium is discovered by Andre-Louis Debierne.

Boatel has a similar meaning to yachtel.

Westinghouse has a similar system, with two classifications representing various levels of competence on the strictly technical side: consulting engineer or scientist, as the case may be, and advisory engineer or scientist.

There is one exception to the above statement as has been pointed out, and that is that fluids can relax by flowing into fields of lower rates of shear, so the statement should be modified by stating that the mechanics are similar.

The Attorney General of the United States, in considering the power of the Secretary to issue similar regulations under the Wagner-Peyser Act relating to the interstate recruitment of farm workers, has rendered an opinion sustaining his authority.

Within each chapter an effort has been made to group together those crystals with similar structures.

The Vedic Rudra has some similar functions with Apollo.

Once a predator has sampled one of these, it is likely to remember the colouration next time it encounters a similar animal.

In Western countries, a bead frame similar to the Russian abacus but with straight wires and a vertical frame has been common ( see image ).

While the Ural – Altaic hypothesis can still be found in encyclopedias, atlases, and similar general references, it has not had any adherents in the linguistics community for decades.

Anatolia's diverse topography and climate has fostered a similar diversity of plant and animal communities.

Malzahar, a character from League of Legends, has a similar back story and Arabian theme that seems to be a direct reference to Alhazred, not to mention the obvious correlation between the two names.

The trump picture of Corwin is executed in a subtly different style-and has features very similar to Roger Zelazny's.

# An adiabat looks similar to an isotherm, except that during an expansion, an adiabat loses more pressure than an isotherm, so it has a steeper inclination ( more vertical ).

Japan celebrates a similarly themed Greenery Day, held on May 4. Although it has a similar theme to Arbor Day, its roots lay in celebration of the birthday of Emperor Hirohito.

The American Psychiatric Association has recommended sustained treatment in conjunction with AA's program, or similar community resources, for chronic alcoholics unresponsive to brief treatment.

) Hilton also claims a Roman Catholic monarch would therefore be unable to be crowned by the Archbishop of Canterbury and points to the examples of European states that have similar religious provisions for their monarchs: Denmark, Norway, and Sweden, whose constitutions compel their monarchs to be Lutherans, the Netherlands, the constitution of which insists its monarchs be members of the Protestant House of Orange, and Belgium, which has a constitution that provides for the succession to be through Roman Catholic houses.

Although systems similar to AARP existed in other systems, Banyan VINES for instance, nothing like NBP has existed until recently.

Tibetan astrology also shares many of these components but has also been strongly influenced by Chinese culture and acknowledges a circle of animal signs similar to that of the Chinese zodiac ( see below ).

He says that the object described by the Lemba has attributes similar to the Ark.

For example, armoured personnel carriers were generally replaced by infantry fighting vehicles in a very similar role, but the latter has some capabilities lacking in the former.

The desire to create air portable armoured vehicles that can still take on conventional MBTs has usually resulted ATGM armed light vehicles or in protected / armoured / mobile gun system style vehicles in which a lack of armour protection being in part offset by the provision of a first look / first hit / first kill capability through the mating of a powerful gun to superior targeting electronics, a concept similar in operation to that of the US tank destroyers of WWII.

While the use of paracetamol, aspirin, ibuprofen, naproxen and other NSAIDS concurrently with weak to mid-range opiates ( up to about the hydrocodone level ) has been said to show beneficial synergistic effects by combatting pain at multiple sites of action, several combination analgesic products have been shown to have few efficacy benefits when compared to similar doses of their individual components.

The ablative case in Sanskrit is the fifth case ( panchami ) in the grammar, and has similar function to that of Latin.

Ajaccio has a small manufacturing economy of cigars, macaroni, and similar products, and carries on shipbuilding, sardine-fishing and coral-fishing.

Each element has a specific set of chemical properties as a consequence of the number of electrons present in the neutral atom, which is Z ( the atomic number ).

Americium ( ) is a transuranic radioactive chemical element that has the symbol Am and atomic number 95.

Teeth of the radula of chiton Chaetopleura apiculata has been studied by atom-probe tomography for the chemical structure and it have been published in 2011.

Atom probe has typically been employed in the chemical analysis of alloy systems at the atomic level.

This has arisen as a result of voltage pulsed atom probes providing good chemical and sufficient spatial information in these materials.

Subsequently, atom probe has been used in the analysis of the chemical composition of a wide range of alloys.

The neutral charge and lower degree of chemical complexity of agarose make it less likely to interact with biomolecules, and, therefore, agarose has become the preferred matrix for work with proteins and nucleic acids.

The chemical industry has remained in good overall condition but is subject to fluctuating natural gas prices.

Pioneer Hi-Bred has marketed corn hybrids with tolerance to imidazoline herbicides under the trademark " Clearfield "-though in these hybrids, the herbicide-tolerance trait was bred using tissue culture selection and the chemical mutagen ethyl methanesulfonate not genetic engineering.

The Swiss chemical industry operates largely from Basel, and Basel also has a large pharmaceutical industry.

The discovery of the chemical elements has a long history from the days of alchemy and culminating in the creation of the periodic table of the chemical elements by Dmitri Mendeleev ( 1834 – 1907 ) and later discoveries of some synthetic elements.

Ninety – four different chemical elements or types of atoms based on the number of protons are observed on earth naturally, having at least one isotope that is stable or has a very long half-life.

In addition the Chemical Abstracts Service has devised a method to index chemical substances.

A molecule is the smallest indivisible portion of a pure chemical substance that has its unique set of chemical properties, that is, its potential to undergo a certain set of chemical reactions with other substances.

The discoveries of the chemical elements has a long history culminating in the creation of the periodic table by Dmitri Mendeleev.

Since the end of the Second World War, the development of computers has allowed a systematic development of computational chemistry, which is the art of developing and applying computer programs for solving chemical problems.

Either in its pure forms, or in various chemical compounds or mixtures, almost every element has at least one important human use.

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 ).

The layout of the table has been refined and extended over time, as new elements have been discovered, and new theoretical models have been developed to explain chemical behavior.

For purposes of international communication and trade, the official names of the chemical elements both ancient and more recently recognized are decided by the International Union of Pure and Applied Chemistry ( IUPAC ), which has decided on a sort of international English language, drawing on traditional English names even when an element's chemical symbol is based on a Latin or other traditional word, for example adopting " gold " rather than " aurum " as the name for the 79th element ( Au ).