element


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element

 [el´ĕ-ment]
1. any of the primary parts or constituents of a thing.
2. in chemistry, a simple substance that cannot be decomposed by ordinary chemical means; elements are the basic components of which all matter is composed.

Chemical elements are made up of atoms, each of which consists of a nucleus with a cloud of negatively charged electrons revolving around it. The two major components of the nucleus are protons and neutrons. The number of protons in the atoms of a particular element is always the same, and therefore the physical and chemical properties of the element are always the same. It is possible, however, for a chemical element to exist in several different forms, the difference depending on the number of neutrons in the nucleus of its atoms. Different forms of the same element are called isotopes.

There are at least 105 different chemical elements known. (See Appendix 6 for a list of the elements, and the symbol, atomic weight, and atomic number of each.) The atomic number of an element is determined by the number of protons in the nucleus of one of its atoms. The mass number of an isotope is determined by the total number of neutrons and protons in the nucleus.
Stable Chemical Elements. A stable chemical element is one that contains an optimal ratio or range of ratios between the number of protons and neutrons in the nucleus. A stable element does not spontaneously transmute into another element and therefore does not give off radiation. The stable elements are those that have an atomic number below 84, except for a few, such as potassium and rubidium, which are weakly radioactive.
Radioactive Chemical Elements. A radioactive chemical element does not contain an optimal proton-to-neutron ratio in its atomic nuclei and therefore readily gives off nuclear particles until all nuclei have attained the optimal combination of protons and neutrons. The spontaneous releasing of its nuclear particles changes the radioactive atom into a new atom (transmutation).ƒ

As radioactive elements disintegrate and form new chemical elements, a tremendous amount of energy is released. This emission of energy and nuclear particles is called radiation. The radiations may be electrically charged particles having size and mass, such as alpha particles and beta particles, or they may be nonparticulate and contain no electrical charges, such as gamma rays. Most radioactive elements give off either alpha or beta particles and at the same time emit gamma radiation.
formed e's of the blood the blood cells.
trace element a chemical element present or needed in extremely small amounts by plants and animals; such elements include manganese, copper, cobalt, zinc, and iron.

el·e·ment

(el'ĕ-ment),
1. A substance composed of atoms of only one kind, that is, of identical atomic (proton) number, that therefore cannot be decomposed into two or more elements and that can lose its chemical properties only by union with some other element or by a nuclear reaction changing the proton number.
2. An indivisible structure or entity.
3. A functional entity, frequently exogenous, within a bacterium, such as an extrachromosomal element.
[L. elementum, a rudiment, beginning]

element

/el·e·ment/ (el´ĕ-ment)
1. any of the primary parts or constituents of a thing.
2. in chemistry, a simple substance that cannot be decomposed by chemical means and that is made up of atoms which are alike in their peripheral electronic configurations and so in their chemical properties and also in the number of protons in their nuclei, but which may differ in the number of neutrons in their nuclei and so in their mass number and in their radioactive properties.
3. in the philosophies underlying some complementary medicine systems, a member of a group of basic substances that give rise to everything that exists.

five elements 
1. see under phase.
2. in ayurvedic tradition, the basic entities (earth, air, fire, water, and space) whose interaction gives rise to material existence.
formed elements of the blood  the blood cells.
trace elements  chemical elements distributed throughout the tissues in very small amounts and that are either essential in nutrition, as cobalt, copper, etc., or harmful, as selenium.
transposable element  see transposon.

element

Etymology: L, elementum, first principle
one of more than 100 primary, simple substances that cannot be broken down by chemical means into any other substance. Each atom of any element contains a specific number of protons in the nucleus and an equal number of electrons outside the nucleus. In most elements, the nucleus may contain a variable number (high or low) of neutrons. An element with a disproportionate number of neutrons may be unstable, in which case the nucleus undergoes radioactive decay into a more stable element. See also atom, compound, molecule, radioactivity.

element

EBM
In the context of a trial design, a basic unit of time within a clinical trial, which describes what is expected to happen to the subject (patient) during the period, when the period begins and rules for ending the element.

Informatics
A section of text in an XML document delineated by start and end tags, or, in the case of empty elements (elements with no content, only attributes), indicated by an empty tag.

el·e·ment

(el'ĕ-mĕnt)
1. A substance composed of atoms of only one kind, i.e., of identical atomic (proton) number, which therefore cannot be decomposed into two or more elements, and which can lose its chemical properties only by union with some other element or by a nuclear reaction changing the proton number.
2. An indivisible structure or entity.
3. A functional entity, frequently exogenous, within a bacterium, such as an extrachromosomal element.
[L. elementum, a rudiment, beginning]

element

(el'e-ment) [L. elementum, a rudiment]
Enlarge picture
TABLE OF ELEMENTS IN THE BODY
In chemistry, a pure substance consisting of only one type of atom. Further breakdown by nonchemical means of an element results in subatomic particles (protons, neutrons and electrons), which are indistinguishable from those from other elements. Elements exist in free and combined states. There are 110 named elements and others yet to be fully characterized and named. See: illustration

Oxygen, carbon, hydrogen, nitrogen, phosphorus, and sulfur are found in all living organisms. These six elements and calcium make up 99% of the human body mass. Sodium, potassium, magnesium, chlorine, iodine, and iron form 0.9% of the body mass.

mobile element

A nucleotide sequence that can be inserted successfully into several different places in the genome.

movable genetic element

Transposon.

rare earth element

One of a series of metallic elements that follow lanthanum (at. no. 57) in the periodic table of elements and that have oxides with similar properties. The series comprises the 14-element lanthanide series (at. nos. 58-71 and includes praseodymium, promethium, and ytterbium.

trace element

An element needed by the body in very small amounts; many are essential for enzyme functioning. Trace elements include chromium, copper, fluoride, iodine, iron, manganese, molybdenum, selenium, and zinc.

ultratrace element

Any of those elements for which laboratory animals seem to have tiny dietary requirements, typically less than 1 µg/g. Elements in this category include arsenic, boron, bromine, cadmium, chromium, fluorine, lead, lithium, molybdenum, nickel, silicon, tin, and vanadium.

element

a pure substance consisting of only one type of atom, that cannot be destroyed by normally available heat or electrical energy.

element

substance composed entirely of identical atoms; it will only lose its unique chemical property by bonding with another element or substance

element,

n any substance that cannot be reduced into a less complex substance, all atoms of which are defined as having the same number of protons.

el·e·ment

(el'ĕ-mĕnt)
Substance composed of atoms of only one kind that therefore cannot be decomposed into two or more elements and can lose its chemical properties only by union with another element or by nuclear reaction changing the proton number.
[L. elementum, a rudiment, beginning]

element,

n a simple substance that cannot be decomposed by chemical means and is made up of atoms that are alike in their peripheral electronic configuration and chemical properties but differ in their nuclei, atomic weights, and radioactive properties.

element

1. any of the primary parts or constituents of a thing.
2. in chemistry, a simple substance that cannot be decomposed by ordinary chemical means; the basic 'stuff' of which all matter is composed.
Chemical elements are made up of atoms. Each atom consists of a nucleus with a cloud of negatively charged particles (electrons) revolving around it. The two major components of the nucleus are protons and neutrons. The number of protons in the atoms of a particular element is always the same, and therefore the physical and chemical properties of the element are always the same. It is possible, however, for a chemical element to exist in several different forms, the difference depending on the number of neutrons in the nucleus of its atoms. Different forms of the same element are called isotopes.
There are at least 105 different chemical elements known. Table 6 lists the elements, and the symbol, atomic weight and atomic number of each. The atomic number of an element is determined by the number of protons in the nucleus of an atom of the element. The mass number of an isotope is determined by the total number of neutrons and protons in the nucleus.

formed e's (of the blood)
erythrocytes, leukocytes and platelets.
element points
trace element
a chemical element present or needed in extremely small amount by plants and animals, such as manganese, copper, cobalt, zinc, iron. See also trace element.

Patient discussion about element

Q. what consider to be a good nutrition for children? does it has to include some specific nutrition elements?

A. there's many things you should consider about children's nutrition, the amount of books written about kids nutrition can fill a library...
vitamins, organic vs industrial, fast food vs home made etc.
here are 2 video libraries that i'm sure you'll find all the info you seek in them-

http://www.thedoctorsvideos.com/categories/26/Nutrition

http://www.drmdk.com/html/nutrition.html

More discussions about element
References in classic literature ?
He ceas'd; and SATAN staid not to reply, But glad that now his Sea should find a shore, With fresh alacritie and force renew'd Springs upward like a Pyramid of fire Into the wilde expanse, and through the shock Of fighting Elements, on all sides round Environ'd wins his way; harder beset And more endanger'd, then when ARGO pass'd Through BOSPORUS betwixt the justling Rocks: Or when ULYSSES on the Larbord shunnd CHARYBDIS, and by th' other whirlpool steard.
Even the raging of the elements round him appeared to add to his exaltation.
I was equally determined to be true to the North, as well as to the best element of the white South, in what I had to say.
Here is how Carlyle describes his new friend: "A fine, large- featured, dime-eyed, bronze-coloured, shaggy-headed man is Alfred; dusty, smoky, free and easy; who swims outwardly and inwardly with great composure in an articulate element as of tranquil chaos and tobacco smoke; great, now and then when he does emerge; a most restful, brotherly, whole-hearted man.
In both cases, the sterility occurs in various degrees; in both, the male element is the most liable to be affected; but sometimes the female more than the male.
First and always in considering any piece of literature a student should ask himself the question already implied: Does it present a true portrayal of life--of the permanent elements in all life and in human nature, of the life or thought of its own particular period, and (in most sorts of books) of the persons, real or imaginary, with whom it deals?
The addition of these elements that go beyond crude sensation is said to constitute perception.
Similarly those abnormal psychic states which are not inborn, but arise from the concomitance of certain other elements, and are difficult to remove, or altogether permanent, are called qualities, for in virtue of them men are said to be such and such.
Here are the exact figures: 25 gallons of water, separated into its constituent elements, yield 200 pounds of oxygen and 25 pounds of hydrogen.
Laws of motion of any kind become comprehensible to man only when he examines arbitrarily selected elements of that motion; but at the same time, a large proportion of human error comes from the arbitrary division of continuous motion into discontinuous elements.
So reconstructed, the earliest period appears to us as a time of slow development in which the characteristic epic metre, diction, and structure grew up slowly from crude elements and were improved until the verge of maturity was reached.
The telegram added that the elements of this new star had not yet been calculated; and indeed three observations made upon a star in three different positions are necessary to determine these elements.