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Harm to minors, violence or threats, harassment or privacy invasion, impersonation or misrepresentation, fraud or phishing, show more. Are you sure that you want to delete this answer? A chemical element, often called simply an element, is a substance that cannot be decomposed or transformed into other chemical substances by ordinary chemical processes. All matter consists of these elements and as ofunique elements Ionization energy definition yahoo dating been discovered or artificially created.
The smallest particle of such an element is an atom, which consists of electrons centered about a nucleus of protons and neutrons. Contents [show] 1 Chemistry terminology 2 Description 2.
However, because of allotropy, the isotope effect, and the confusion with the more useful term referring to the general class of atoms irrespective of what compound it may be inthis usage is in disfavor amongst contemporary chemists, and sees restricted, mostly historical, use. This definition was motivated by the observation that these elements could not be dissociated by chemical means into other compounds.
For example, water
Ionization energy definition yahoo dating be converted into hydrogen and oxygen, but hydrogen and oxygen could not be further decomposed, thus "elemental". There are also many counterexamples for example "elemental oxygen" O2 can be decomposed by solely chemical means into oxygen ions and atoms which have drastically different chemical properties.
This article will concern itself with the latter definition. All the heavier elements are made, both naturally and artificially, through various methods of nucleosynthesis. As ofthere are known elements: The 23 elements not found on earth Ionization energy definition yahoo dating derived artificially; technetium was the first purportedly non-naturally occurring element to be synthesized, inalthough trace amounts of technetium have since been found in nature, and the element may have been discovered naturally in All artificially derived elements are radioactive with short half-lives, so if any atoms of these elements were present at the formation of Earth they are extremely likely to have already decayed.
Lists of the elements by name, by symbol, by atomic number, by density, by melting point, and by boiling point as well as Ionization energies of the elements are available. The most convenient presentation of the elements is in the periodic table, which groups elements with similar chemical properties together. These atoms may have different numbers of neutrons, which are known as isotopes of the element. Since electrons are of negligible mass, and neutrons are barely more than the mass of the proton, for lighter elements this often corresponds to the
Ionization energy definition yahoo dating of the protons and neutrons in the nucleus of the most abundant isotope.
However, particularly with heavier elements, more than one stable isotopes contributes significantly to the average atomic mass. An example is chlorine, which is about three-quarters 35Cl and a quarter 37Cl. The atomic masses that are given on the periodic table are actually the mean abundance-corrected atomic masses for natural samples of the element, which are calculated by the following method. As an example, assume there naturally exist two isotopes of chlorine with respective atomic masses 35 and 37 AMU.
For an element with three naturally occurring isotopes the method is the same: This method of calculating the average mass takes into account the relative abundance of all of the isotopes of an element, so that this mass number always gives the same total number of atoms, for a natural sample of any element. This allows for approximate counting of atoms in a natural element sample, by simply weighing the sample.
There are many instances in nature particularly with light and volatile elements where isotope ratios are slightly affected by natural sorting processes, but in most cases the atomic masses given may be used to estimate number of atoms in a natural sample to four or more significant figures. Certain elements have no nonradioactive isotopes: When it was learned, existing names e. That organization has recently prescribed that "aluminium" and "caesium" take the place of
Ionization energy definition yahoo dating US spellings "aluminum" and "cesium," while the US "sulfur" takes the place of "Ionization energy definition yahoo dating" British "sulphur.
According to IUPAC, the full name of an element is not capitalized, even if it is derived from a proper noun such as the elements californium Ionization energy definition yahoo dating einsteinium unless it would be capitalized by some other rule, for instance if it begins a sentence, or an article or subsection title in a Wikipedia article.
Isotopes of chemical elements are also uncapitalized if written out: In the second half of the twentieth century physics laboratories became able to produce nuclei of chemical elements that have a half life too short for them to remain in any appreciable amounts. This can lead to the controversial question of which research group actually discovered an element, a question which delayed the naming of elements with atomic number of and higher for a considerable time. See element naming controversy.
Precursors of such controversies involved the nationalistic namings of elements in the late nineteenth century. For example, lutetium was named in reference to Paris, France. The Germans were reluctant to relinquish naming rights to the French, often calling it cassiopeium. The British discoverer of niobium originally named it columbium, in reference to the New World. It was used extensively as such by American publications prior to international standardization. These were however used as abbreviations in diagrams or procedures; there was no concept of atoms combining to form molecules.
With his advances in the atomic theory of matter, John Dalton devised his own simpler symbols, based on circles, which were to be used to depict molecules.
The current system of chemical notation was invented by Berzelius. In this typographical system chemical symbols are not used as mere abbreviations - though each consists of letters of the Latin alphabet - they are symbols intended to be used by peoples of all languages and alphabets. The first of these symbols were intended to be fully universal; since Latin was the common language of science at that time, they were abbreviations based on the Latin names of metals - Fe comes from Ferrum, Ag from Argentum.
Ionization energy definition yahoo dating symbols were not followed by a period full stop as abbreviations were. Later chemical elements were also assigned unique chemical symbols, based on the name of the element, but not necessarily in English.
For example, sodium has the chemical symbol 'Na' after the Latin natrium. The same applies to "W" wolfram for tungsten, "Hg" hydrargyrum for mercury, "K" kalium for potassium, "Au" aurum for gold, and "Sb" stibium for antimony. Chemical symbols are understood internationally when element names might need to be translated.
There are Ionization energy definition yahoo dating differences; for example, the Germans have used "J" instead of "I" for iodine, so the character would not be confused with a roman numeral.
The first letter of a chemical symbol is always capitalized, as in the preceding examples, and the subsequent letters, if any, are always lower case small letters.
These are one capital letter in length, and the letters are reserved so they are not permitted to be given for the names of specific elements.
For example, an "X" is used to indicate a variable group amongst a class of compounds though usually a Ionization energy definition yahoo datingwhile "R" is used for a radical, meaning a compound structure such as a hydrocarbon chain.
The letter "Q" is reserved for "heat" in a chemical reaction. This is in order to make it easier to use them in chemical equations, as it replaces the need to write out the AMU for each isotope.
It is written like this: D2O heavy water Instead of writing it like this: Element Parts per million HydrogenHeliumOxygen 10, Carbon 4, Neon 1, Iron 1, Nitrogen Silicon Magnesium Sulfur  Recently discovered elements The first transuranium element element with atomic number greater than 92 discovered was Neptunium in The heaviest element that has been found to date is elementUnunoctium, which was successfully synthesized on October 9,by the Flerov Laboratory of Nuclear Reactions in Dubna, Russia ElementUnunseptium, is yet to be created or discovered, although its place in the periodic table is preestablished, and likewise possible elements beyond.
An element is a substance that cannot be changed into other chemical substances by ordinary chemical processes. The smallest particle of an element is an atom, which is made of electrons centered about a nucleus containing protons and neutrons. A compound is a chemical substance consisting of two or more different chemically bonded chemical elements, with a fixed ratio determining the composition. The ratio of each element is usually expressed by chemical formula.
For example, water H2O is a compound consisting of two hydrogen atoms bonded to an oxygen atom. The atoms within a Ionization energy definition yahoo dating can be held together by a variety of interactions, ranging from covalent bonds to electrostatic forces in ionic bonds. A continuum of bond polarities exist between the purely covalent bond as in H2 and ionic bonds. For example H2O is held together by polar covalent bonds. Sodium chloride is an example of an ionic compound.
Elements are the "building blocks" of matter. Compounds are substances made up of elements which are combined in a specific way. The only known elements are those within the periodic table, but the number of possible compounds is huge, due to the fact that many elements can be combined in many ways. The "stuff" is composed of only one kind of atom. Pure water is H2O. Two Hydrogen Ionization energy definition yahoo dating bound to each Oxygen molecule.
Hydrogen and Oxygen are both elements you can find on the periodic table. The confusion for me when I was in school, was the difference between a compound and a mixture.
I used to think about milk to help me remember. You can't write a formula for milk like I did above for water. The proportions of milk can vary. There may be more or less water, protein, milk sugar lactose or milk fat Another example of a mixture is tap water. You can't write that as just H2O because there is chlorine in it and minerals and contaminants. An -element- is basically made up of atoms with the same number of protons. Yes, an element is a particular type of atom.
Atoms are of course composed of protons neutrons and electrons. The number of protons determines the type of atom. For example Hydrogen has one proton in its nucleus Ionization energy definition yahoo dating carbon has 6. That's what makes hydrogen hydrogen and carbon carbon.
The atomic number on the periodic table is the number of protons. A compound is composed of multiple elements like water which has two hydrogen atoms and one oxygen. Elements are substances with only one atom Compounds are a number of elements chemically joined together Mixtures are substances NOT Ionization energy definition yahoo dating joined together such as sea water - as salt is disolved in it, not chemically combined to it Hope thats what you wanted.
Elements are substances made from the same type of atoms e. O2 OxygenN2 Nitrogen Compounds are sustances made from different types of atoms e. CO2 carbon dioxide is made from one atom of carbon and two of oxygen. Don't understand the question but Have a look on http: Fill in the blank: This page describes specific privacy practices with respect to Yahoo Answers, Yahoo Autos, Yahoo Celebrity, Yahoo Finance, Yahoo Movies, Yahoo Music, My.
As you proceed from left to right the trend on the periodic table is for the ionization energy to increase.